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.
I have a camper trailer with a water tank. Do I need a pump to get water from the tank to the HOTTAP?
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.
You can definitely use a gravity system at home to run the HOTTAP however please be mindful that you will require a specific set of conditions in order to meet adequate operation of the system.
You'll need 10PSI minimum to open up the pressure switch on the inside of the unit and you'll need 6LPM flow rate as well.
Usually we find that with gravity systems (this is assuming a tank 10-15m above the shower on the side of a hill) has enough pressure to fire up the HOTTAP on the lowest flow setting, but then once you try to adjust the dial to anything more than 1/4 water flow, the unit will cut out.
This is because there isn't enough water flow and pressure to keep that pressure switch inside the unit opened up, so it closes up and the system shuts down.
If the tank you're talking about is anything less than 10m above the shower, then you'll run into issues. If you're not running through the HOTTAP than gravity fed shower is OK, it's just when you want to connect to the HOTTAP you'll need to make sure you have enough pressure/water flow.
Reason for that is the size of the burners are designed for a certain water flow/pressure. If the water flow comes in at a much lower flow rate, then the water will heat up very very quickly way beyond the safety cut-off of 50C (basically it'll be useless as you can't have a shower).
From past experiences we have found in many cases it is easier to obtain a pump to enjoy the system to its full potential.