We supply a Standard Propane Regulator (screw-on type) which is suitable for use with Propane Bottles between 3.9kg - 47kg. These are the Red bottles and are readily available from Flogas and Calor.

We recommend the use of Standard Propane over Butane gas in general due to better performance in lower temperatures. We also recommend it over Patio Gas because Patio Gas Refills are often more expensive per the same amount of propane purchased. Having said that, other gas types are safe to use with your Joolca and you are free to do so, but you'll need to purchase a compatible regulator.

The HOTTAP v2 comes in 3 models: HOTTAP Essentials, HOTTAP Outing and HOTTAP Nomad.

Click on your country to view the differences, including prices, on our website: AU, NZ, USA or UK. Otherwise, read on.

What comes with the HOTTAP Essentials and is it right for me?

The HOTTAP Essentials is the base model and it does not come with a pump kit.

What's in the box?

The HOTTAP needs a pressurised water source in order to work, so you should only consider the HOTTAP Essentials if you already have a pump or another suitable water source. Eg. Council mains (garden tap at home) or a gravity-fed system. 

When to consider the HOTTAP Essentials:

• You want to hook it up to your backyard shed and already have access to a garden tap
• You want to wash your dog and already access to a garden tap
• You want to use it on your off-grid property and already have access to a suitable gravity-fed system
• You want to use it on your camper trailer and your trailer already comes with a suitable pump
• You want to use it camping and you already have a suitable pump

We also have a bunch of accessories, including a 12V pump kit (the same one that comes with the HOTTAP Outing). So, if you grab the HOTTAP Essentials and down the track you realise you want to get a pump, you can always upgrade.

What comes with the HOTTAP Outing and is it right for me?

The HOTTP Outing is one step up from the HOTTAP Essentials since it comes with our 12V pump kit. (This is the only difference between the Essentials and Outing). 

What's in the box?

The HOTTAP Outing is a fully portable solution. You will still need to provide power to the pump (eg. plug it into a portable battery or your car cigarette socket), and then you're good to go. 

When to consider the HOTTAP Outing:

• You want to go camping and you don't have a pump
• You want to use it on your camper trailer and don't want to use the existing water supply (eg. want to pump from a river or creek)
• Your current setup isn't suitable to run the HOTTAP
• You just want a spare pump

Cool setup idea

The FLOTAP pump is able to push water 20-30 metres. So, a common setup is to get a 20-30 metre coil of hose and pump water directly from the river to your campsite. Here is how you would set this up. You can also grab an extension hose from our website. 

What comes with the HOTTAP Nomad and is it right for me?

The HOTTAP Nomad is the highest upgrade. It includes an upgraded stand (the Essentials and Outing have 2x lightweight feet, and the Nomad has a sturdier stand), a sink/ carry tub and a faucet tap—to help with washing up dishes.

What's in the box?

The HOTTAP Nomad is still a fully portable solution, just like the HOTTAP Outing. The tub triples up as a (1) sink—so you can wash and dry dishes, (2) store water and (3) store your HOTTAP and all the Nomad parts.

When to consider the HOTTAP Nomad:

• You want to be able to wash dishes when camping or off-grid
• You want to run multiple lines out of the HOTTAP for a longer-term trip
• You like the idea of a tub to store everything as well as to hold water
• You want to use the tub around the home

Cool setup idea

A great camping setup with the Nomad (and any HOTTAP model) is to use it with the ENSUITE Tent. With the Nomad, you can run one water line to your sink/ tub and another line directly into your ENSUITE Tent. Keep in mind that you can only use one line at a time (ie. either shower or wash dishes, and not both at the same time). And if you run the FLOTAP directly from a creek, you have endless water for all your hot water needs!

No. Do not use the HOTTAP inside an enclosed space.

Using the HOTTAP inside an enclosed space is a Carbon Monoxide Hazard. Do not use the HOTTAP inside caravans, tents, cars, mobile homes, or similar locations.

Please refer to the below Safety Instructions for more information:

We've had people use it for this exact situation. It works, but there are a few things to be mindful about.

Temperature Increase

The hottest increase the incoming water is by 30-35C (86-95F) above the incoming water. This is on the highest gas / lowest water flow setting.

Say the water coming in is 10C (50F) from the tap - the HOTTAP will get it to 40-45C (104-113F), but the water will be set to the lowest setting (i.e approx 4LPM (1GPM)). So it might take a while before the bath is fully filled up

Recirculating the Water

Another idea is to circulate the water, but using a pump. Start by filling your bath up with water, then use a pump to recirculate water inside the bath (simply put the suction hose into the bath) and whatever is coming out the Hottap goes back into the bath.

You might find it's quicker to fill up the bath from the tap, then just recirculate water, and over time it'll heat up nicely. Using this method, the longer you keep recirculating water you can heat it up quite hot - as the water inside the bath will slowly get warmer over time.

However using the pump, we only recommend a max cycle time of 20min at a time. We've seen our pumps working for more than 20min at a time without trouble but again something to keep an eye on so the pump doesn't overheat.

Protecting from Wind

Assuming the Hottap will be running for a while, and if it's in an area where it's prone to winds, there is a chance that the flame could blow out. If the flame goes out the Hottap won't automatically shut the water flow, so you'll have to keep an eye on it to make sure you're actually getting warm water coming out.

All gas appliances are adjusted for a gas + oxygen mixture as 'sea' level. As you go up in altitude, there is less air and the combustion is less efficient. 

At around 1500m (5000ft) we estimate that the HOTTAP will be around 10% less efficient. The higher up you go, HOTTAP will work but it'll just take longer for your water to heat up, or it won't get as hot. You can mitigate this by just recirculating water in a tub if you need to get it to reach a higher temperature. 

Sizing Charts

Tub Storage Capacity: ~50 Litres / 14 Gallons

Specifications Table: 

Hottap is activated by water pressure. Before you have water flowing, or if you don't have enough flow (or pressure), nothing will happen. As in, HOTTAP won't make any sounds and the LED won't light up. Note: You can troubleshoot this issue by pressing and holding the 'Joolca' Icon on the LED screen and observing if the water flow error icon illuminates - read more Troubleshooting HOTTAP v2

As the water flows through HOTTAP, a sensor picks up the water flow rate and opens a gas solenoid valve, which allows the gas to flow into the burners and ignite. At this point, you'll hear a loud clunk (solenoid opening) and fast ticking (the ignitor). 

This whole ignition system is powered by the two d-cell batteries. They are also what power up the LED screen. Because juice is only drawn when HOTTAP is active (and not much power is taken anyway) they last for quite a while. Normally at least 6 months, but it depends on your usage. 

Once the HOTTAP is active, you can look through the slits above the control dials to see the flame. Adjusting the flame toggle will increase or decrease the size of the flame and thus the heat output. Adjusting your water will either reduce or increase the speed at which the water flows through the heat exchanged. Faster flow = less time to absorb heat, therefore less hot water. Slower flow, hotter water. 

If you're using our 12V pump, that runs off a separate 12V power supply, namely a cigarette socket or any other 12V supply that you might have. Our pumps have a sensor which can tell when the water flow has been turned on / off.

What this means for you is that you can have your shower or faucet all set up, and by simply flicking the water flow on, the whole system will work automatically to start the water flow and heat the water up. When you're done, that same switch will shut everything off. 

Parts Overview

1. HOTTAP unit
2. GasKnect snap-on fitting
3. 1.2m Gas hose
4. Lightweight feet**
5. Shower-head
6. 4m shower hose
7. 1m shower hose
8. Shower handle with switch
9. Magnetic shower handle holder
10. Hose coupling connector
11. Three-way hose splitter

*Your kit may contain additional accessories, please consult your quick start guides for more information

** Nomad kit includes a Heavy duty stand in place of Lightweight feet.

Setting up HOTTAP

Before setting up, please note that Hottap requires a water pressure of at least 70kPa to work. This part of the guide assumes that you have access to mains water.

For use with the Off-Grid Plumbing kit, please refer to pages 20-21.

To set up your Hottap for use, please cover the following steps: 

Step 1)

Install 2 D-cell batteries observing the labelling on the battery box and the batteries.

Step 2) 

Using a spanner, connect the female GasKnect fitting to the gas hose.

Do not use thread tape

Connect the regulator to the gas bottle and the GasKnect to the Hottap unit.

The gas cylinder must be positioned away and to the side of the appliance. It must never be directly beside, below or above the appliance.

Step 3)

When mounting your Hottap, please ensure that there is sufficient clearance from people and combustible materials: at least 1,000mm from the top, 600mm at the rear and at least 500mm from the sides and front of the unit.

Depending on what particular Hottap kit you own, you may mount it in one of three ways:

3.a. Heavy-duty stand Connect all hoses (see point 4.) and place unit into the heavy-duty stand.

3.b. Hang the Hottap on a suitable vertical surface

3.c. Lightweight legs Fasten the lightweight feet with the captive thumb screws.

Step 4) 

Attach the red shower hose to the red quick connect fitting.

Connect the blue hose to your water source and to the blue quick-connect fitting on the Hottap.

Attach the GasKnect brass fitting to the gas inlet.

Step 5) 

Connect the regulator to the gas cylinder. Open the gas cylinder by twisting the valve knob in an anti-clockwise direction one full turn.

Check the entire gas line for leaks by coating the hose and connection points with soapy water. Do not use a flame. If bubbles are formed or you can hear a leak, turn off the gas at the cylinder. Tighten all connections and test again.

Once you have determined that there are no leaks, the appliance is ready to use.

Turn the gas off.

You might also be interested in a quick set up guide for operating the HOTTAP v2, which can be found here 

1. Remove the red plugs from the inlet and outlet of the pump.
2. Snap the hoses onto the quick-connect fittings on the water inlet and outlet.
3. Set up your filter for intended use - i.e. with or without the intake collar - and attach to end of pump inlet hose. Drop or throw filter into water source.
4. Observing the flow direction of the pump, attach the pump outlet hose to the blue quick-connect fitting on the Hottap.
5. Plug the lighter port cable into the pump and connect to power.
6. Press the power button on the pump, leaving it in the “on” position. You can now start and stop the pump (as well as the Hottap) simply by flicking the switch on the shower or faucet handle.

In the US, the most common style of garden hose comes with 3/4" threaded fittings for the connections. To connect this to the HOTTAP you'll need to purchase an adapter, there are two options and both are widely available at your local hardware store: 

Option 1: 

The simplest method is remove the blue water inlet quick-connector and attach an adapter to allow for a direct connection with your garden hose. 

A suitable adapter is something like this one and the water inlet will now look like this. Note: use thread tape for a secure and watertight fit. 

Option 2: 

This option is better if you'd like to keep the 'quick connect' features across the whole system. 

Using any standard garden hose with typical 3/4" Threaded connections, you can purchase an adapter kit which will convert both ends of your hose to a quick connect, allowing you to connect directly to the HOTTAP water inlet, as well as using to extend the reach of your pump. 

Something like this will work well, but any similar brand will also work. 

If you'd haven't already done so, we recommend reading the quick 'set up' guide for HOTTAP v2 by clicking here

Step 1) 

Ensure that the shower handle switch is in the “off” position.

Step 2) 

Turn the gas on by twisting the cylinder valve knob in an anti-clockwise direction one full turn.

Step 3) 

Open the valve at your water source. Please note that, since the shower handle switch is in the “off” position, water should not be flowing through the showerhead

Step 4) 

You can now control the entire system at the shower handle switch. Flick it on: the water starts to flow and the Hottap burner automatically ignites. Flick it off: the water flow stops and the Hottap burner automatically extinguishes.

Bearing in mind that the water might be very hot, stand clear of the shower when turning it on.

Step 5) Setting your temperature

Adjust the red flame lever and the blue water flow dial to find your desired temperature and flow rate.

For higher temperatures, turn the flame up and the water flow down.

For lower temperatures, turn the flame down and the water flow up.

Jump to:

• Mounting HOTTAP V2 using the Joolca Quick Release Mounting Bracket
• Mounting HOTTAP V1 using the Joolca Quick Release Mounting Bracket
• Inspiration on other ways to mount your HOTTAP (V1 & V2)

Does it handle rough roads and corrugations? 

The HOTTAP is built to be robust and handles off-road conditions and corrugated roads with no trouble. At this stage, there are many HOTTAP units sitting on camper trailer drawbars and toolboxes travelling all over.

Are there any safety concerns?

The most important thing to remember is that the HOTTAP is not able to be permanently connected to a reticulated gas supply. What this means essentially is that it's OK for your HOTTAP to be fixed or mounted to your vehicle, but the gas connection should be made each time you set up and it must be disconnected before travelling again. 

It's also important to comply with the clearance instructions listed at the back of the unit while in use. 

Other ways to mount your HOTTAP 

We've got a clever bunch of customers who love to hack up their own mounting set-ups. For some inspiration, you can visit our Facebook or Instagram

TV Mount 

Using a TV mount allows you to conveniently store or swivel out to use when needed.

Drawer Slides

Compartmentalize your HOTTAP by bolting it to drawer slides.

Trailer door and van door mount

HOTTAP v2 stand and feet

Hanging your HOTTAP 

All HOTTAPs come with a handle to conveniently hang your unit.

Adjusting the gas and water dials will let you control the temperature of the water coming out of your HOTTAP. 

Sections in this article:

• Adjust the gas dial
• Adjust the water dial
• How do I get the hottest water?
• How do I see the temperature of the water?

Read on or watch this video. [2 min]

Note: the video mentions the max heat output is 30C. The actual max heat is 35C!

Adjusting the gas and water dial to adjust the temperature

The HOTTAP has the ability to adjust the gas and water flow.

Adjusting the gas

• Setting the gas dial to minimum gives less heat. 

The minimum setting means there is less gas, which produces a smaller flame. And a small flame results in less heat.

• Setting the gas dial to maximum gives more heat. 

The maximum setting means there is more gas, which produces a larger flame. And a larger flame results in more heat. 

Adjusting the water

• Setting the water dial to minimum gives more heat. 

The minimum setting means the water is flowing slower—or, 2.5 LPM. The slower the water, the more time it spends picking up heat. The hotter it gets. 

• Setting the water dial to maximum gives less heat.

The maximum setting means the water is flowing faster—or, 6 LPM. The faster the water, the less time it spends picking up heat. The 'less hot' it gets. 

How do I get the hottest water?

To get the hottest water, set gas to maximum and water to minimum. This gives you a 35C rise in temperature, from your input water. 

How do I see what temperature of the water?

You can view the temperature of the water coming out of the unit by using the monitor.

The HOTTAP needs to be used with mains water, a pump, or another pressurised water source. The HOTTAP unit itself does not have the ability to draw water from a source.

The HOTTAP needs a pressurised water source in order to work. Basically, you need to be 'pushing' water into the HOTTAP, in order for it to turn on. 

Well, you still need batteries and gas: and you can find more info here.

What does this mean

The HOTTAP needs a way to turn on and off automatically. This way you don't need to stand near the unit and keep flicking a switch. To do this, the HOTTAP has a way of sensing water flow. And so that it runs safely and smoothly, it needs a minimum amount of water flow (otherwise it would be on all the time).

The HOTTAP needs a minimum of 6 litres/min and 10 PSI to work on the maximum flow setting. The maximum flow setting is having the water dial set to max, where we have the most water flow.

Imagine having a crowd of people leaving an empty room, through one walkway. We need to have 6 people walking out of the room at one time—this is the water flow. And we can't just have them walk, oh no, we need them to jog. So we give them a little nudge—this is the water pressure. 

And there you go, we have enough water flow and pressure.

Thankfully, we have a few ways of doing this.

Which water supplies will work

All of these will work.

The Joolca FLOTAP pump

Of course. This is how the setup looks.

A pressure pump with 6 litres/ min and 10 PSI to work on all the water flows.

• Just like the room analogy. If we only have a 4 litre/ min pump—or only 4 people leaving the room at a time—well since 4 is less than 6, we can't use the max water setting. Although, we can still turn the HOTTAP on. We'll only be able to use the middle setting. Any higher and the unit will turn off. 
• Read more about pumps here.
• Will my existing pump work?

A garden tap

• If you're using council mains (in a domestic area), all good. 
• If you're on an off-grid property and have your own 'local' water supply, this should work. Although, if you have a super high flow pump (eg. 50+ litres/ min) and super low pressure (less than 10PSI), this could be an issue. It's like now trying to push 50 people at a time out of that same 6 person walkway. People will stumble and fall. And after all the havoc, you might only have a handful of people leaving at a time. And with not enough force. If you have issues with this setup, we recommend another pump. 

Gravity-fed or header tank

More info here.

When it comes to pumping water there is a vast amount of options available to choose from however you need to be certain of the requirements in your system otherwise you are likely to find that the particular pump you have is not fit for purpose.

The Joolca branded pump is specifically designed to be used with the HOTTAP, however if you have your own pump or have a use case with the Joolca pump won't suit, that is perfectly fine. 

General Specifications Required: 

When it comes to the HOTTAP Hot water system the ideal specifications for the pump are that it flows at least 6 litres per minute and no more than 12. You are also looking for a pressure level around 60 PSI. Meeting these operating ranges will ensure optimal operation from the HOTTAP system.

Main types of pumps you may come across are:

Centrifugal water pumps:

These style of pumps generally consist of one or more impellers typically driven electrically. You will find Bilge pumps fall under this category. These style of pumps are not suitable for the HOTTAP due to their nature of providing high water flow rates but low water pressure. We have found from past experience that generally these will not have the required water pressure to activate the pressure switch in the HOTTAP.

Positive displacement pumps (AKA Pressure Pumps):

PD pumps do not have impellers, instead, they consist of either rotating or reciprocating parts and generate high pressure to push the water along the system. These style of pumps will generally provide lower flow rates than centrifugal style pumps however provide much higher water pressure. These style of pumps are ideal for the HOTTAP system and as long as the specifications are within 6-12 litres per minute and around 60 PSI it will be perfect for the HOTTAP system. 

The Joolca FLOTAP has been extensively engineered and tested to push water over a long distance so you will easily be able to push water over 20-30 metres.

Although the pump is also able to pull water due to its specific design it is much better at pushing hence if you are pulling water expect around 1.8m pulling vertically and around 5 metres depending on angle of slope.

As you can see from the above the best way to set the pump up is close to your water source and lead the longer hose all the way to the camp site. This will allow you to fully appreciate the systems capability and truly enjoy that hot shower in the bush!

If you have a camper trailer with an onboard water tank, you may already have a pressure pump onboard. If you do have a pump, make sure it can provide anywhere from 6-12 LPM (litres per minute) and you'll be fine.

Then it's a matter of connecting your existing pump to the HOTTAP and you're good to go!

If you don't have a pump however, then you're best bet is to get the HOTTAP OUTING, which includes a 12V pump kit to be able to take water from the tank and push it through the HOTTAP.

You won't be able to just connect the HOTTAP to the water tank, as gravity won't provide enough pressure to get water flowing properly through the HOTTAP - that's why you always need pressurised water - either water from a garden tap at home, or a 12V pump if you're free camping. 

The HOTTAP requires a minimum of 10PSI and 6LPM to operate across the full flow range.

You’ll find that a lot of pressure pumps will have a pressure setting of at least 40PSI. So, the important thing to focus on is the flow rate.

If you use a lower flow pump (e.g. 4.3LPM) you will be able to use the HOTTAP on the minimum flow setting, but, the unit will cut out as you increase the water dial toward maximum. This is due to the unit requiring more water than what is being supplied.

HOTTAP uses two 'D-Cell' batteries, these power the unit itself as well as the LED screen and generally last for 3-6 months, depending on use. 

The pump connects to a 12V supply (we give you a 5m cigarette socket cable) and draws approximately 3-4 amps depending on your settings. 

The HOTTAP unit itself runs on LPG / Propane. For more information about the types of gas read here. For information about the sizes of bottles you can use read here. 

A 9kg gas bottle can get up to 15 hours of use and a 4kg up to 7 hours, this is on the gas being set to the highest settings. In summer or warmer climates, you probably won't have the gas set this high. Needless to say, it's a pretty long time! 

For the Americans, a 20 lbs Tank will yield around 12 hours. It's a little less than the longevity of the Australian Spec unit and that's because we're allowed to have a higher gas flow setting for you. This is a good thing because it means you can get heat more water which comes in handy in cold conditions. Again, this is on the 'high' setting. 

The easiest way to explain it is that the HOTTAP runs on the same gas that your home BBQ does.

In Australia

We use (most commonly) 9kg LPG cylinders.

In NZ

The cylinders used are nearly identical but they're labelled as 'UPLG' instead. The 'U' stands for 'Universal and it's because in New Zealand (and many other countries) the mix proportions of Butane and Propane in the cylinder can vary quite a lot, whereas in Australia it's fairly consistent. It's not a concern and HOTTAP has been tested and approved with a much wider range of propane-butane mixes than would be found. 

In the United States

This is called a Propane Tank and the standard size is 20lbs but they can also come smaller. 

In the UK

We recommend the use of Standard Propane over Butane gas. Read more on UK gas info here.

For information about the different size bottles, check out this article

The HOTTAP can be connected to a bayonet fitting, however, the only hosing we offer with the HOTTAP is a 1.2m Gas Hose and Regulator (as standard). Any other fittings that maybe required to fit onto a bayonet can be sourced from a hardware or plumbing store.

All HOTTAPs include our gas quick disconnect adapter, to allow your to connect your gas to HOTTAP (and other appliances) without the need to tighten the fittings with a spanner and check for leaks at each use. 

The Gas hose we supply is a standard BBQ style LPG / Propane hose. This varies from region to region, rest assured that the hose you'll get will be the right one for your country. 

Check out some of these helpful links:

• UK gas information
• Ho much gas does it use
• What type of gas do I need
• What size gas tank can I use

If you'd like to know more about what 'type' of gas you need, read this article

In Australia and NZ

9kg Cylinders

The standard and most common size is a 9kg LPG cylinder, but LPG cylinders are quite common in other sizes right down to around 4kg. Just make sure that the cylinder has a POL connection to attach to the gas hose which is supplied. 

2KG Cylinders

Smaller bottles down to around 2kg have also been known to work well but will require adapters to connect to the gas hose we supply.

A common 2kg cylinder will have a 3/8" Threaded outlet, for these you can purchase an adapter like the one in the picture below which will connect to your standard BBQ gas hose. 

The left side thread is 3/8" LH (Left Hand) BSP and the right side is a standard POL Connector (to your gas hose). 

United States

20 lb Tank

In the United States, you can use a propane tank size right down to around 4.5 lb, the main thing is to make sure it's compatible with the supplied gas hose (it's called a QCC 1 Connection on the bottle side).

1 lb Cylinders: 

To use a 1 lb cylinder, you will need a purchase an adapter like this one (Home Depot) or this one (Amazon) which will allow you to use your Joolca supplied hose to connect to the smaller cylinder.

United Kingdom

3.9kg - 47kg:

We supply a Standard Propane Regulator (screw-on type) which is suitable for use with Propane Bottles between 3.9kg - 47kg.

The HOTTAP has a max temperature output of 50 degrees Celsius (122F). The temperature rise is dependent on the settings you have the HOTTAP on.

Low water & high gas = 35C increase (95F)
High water & high gas = 20C increase (68F)

For example, if you had the HOTTAP set at Low water and high gas and you were drawing water from a lake that was 10C (50F), the output would be 45C (113F).

1. Adjust the gas regulator and water regulator to meet your desired temperature. To increase temperature as high as possible; turn the gas regulator control from LO to HI and turn the water regulator control from HI to LO.
2. Check source water temperature. If the source water temperature is too cold then you may need to ‘cycle’ the water through the system back into the source reservoir then through the appliance again to meet your desired temperature.
3. Check if there is a flame in the ‘viewing window’. If you cannot see a flame it could mean that the unit has switched off / not ignited, try restarting the unit and monitor the 'viewing window' for a flame.

If you've connected your HOTTAP Outing, and when the pump is on (and making noise) you have no water flow, or very little, try the following:

1. First and foremost, make sure you've removed the red lugs from the pump inlet and outlet adapters. These lugs are placed here from the factory to keep the lubricating liquid inside the pump during transit, but need to be removed before use otherwise you will not get any water flowing. 
2. Ensure that your 12V supply is charged. If you are running from your car's cigarette socket adapter, try turning the car on. Some cars have safety mechanisms in place which turn off power to accessories when the car is off to stop battery drain. 
3. Check that all fittings, connections and adapters are tight. Also check that your inlet filter is clean and not blocked. Similarly, check the HOTTAP inlet water adapter for blockage. 
4. Try running the pump on its own - not connected to the HOTTAP water heater. That is, have the suction hose sitting in your water container, and the outlet hose running back into this container, to see if this makes any difference. If it still doesn't work, try removing the outlet hose totally, so that the pump is running with just the suction side - this will help the pump prime if that is the issue. Please keep in mind that there may be times when it may take a little while for the pump to actually prime fully so don't hesitate to leave it running for up to 30-60 seconds.

Firstly, make sure you've adjusted the gas and water control knobs (red for gas, blue for water) to set your temperature. For hottest water, gas should be set to HI, and water to LO. Conversely, for coldest water, gas should be set to LO and water to HI. 

If the water temperature is getting too hot, even when you increase water flow to HI and heat to LO it usually is a poor water supply issue. The water is flowing through the HOTTAP too slowly and as a result heating up very quickly. Check the following things:

1. Incoming water temperature is too high. For example, if you have a long water inlet hose, the water in the hose can heat up in the sun – as soon as you turn on the HOTTAP the incoming water temperature is high, and the temperature shoots to 50C and will turn the unit off (safety cutoff). If this happens, try ‘flushing’ the hot water through (turn off gas so the HOTTAP doesn’t ignite a flame). After 30-60 seconds of flushing, the water in the hose should be back to normal. Turn on the gas and try again.
2. There is a blockage somewhere. This will be obvious as there won’t be any difference between the water flow out of the shower hose between the low water flow setting and high water flow setting. Usually there is a big difference between low flow and high flow. If there isn’t, it could be a blockage in the shower head, HOTTAP water inlet filter (you need to unscrew the blue quick connect adaptor), or a blockage in the pump filter.
3. If you are running off a 12V pump, check the suction side filter to make sure it is clear. If not, the pump will put out a lower flow and pressure - this will cause the water to heat up quickly. Also make sure the pump battery is fully charged. A pump running off a 50% full battery will also run at a lower flow and pressure.
4. Check the specifications on your pump (if not a Joolca pump). You should have a pump which is capable of a flow rate between 6-12LPM and a pressure setting of 40-60PSI. Anything less than 6LPM and the HOTTAP may turn off as the pump can’t supply enough water at the high water flow setting. Anything more than 12LPM and you will find your pump pulsates (goes tick tick tick tick) when you turn the water flow setting to low on the HOTTAP.