As we come into the colder part of the year, I find my instantaneous water heater struggles with the incoming water temperature, its designed to work with a 15 degree incoming temperature, I use a 40 L aquaroll with a float from the mains hook up to keep it constantly filled, have the barrel rised off the ground to stop the cold getting into the barrel, but with the water coming in at 8/9 degrees it’s hard , someone suggested putting a heater in the barrel, like you see in a fish tank , any other suggestions would be most welcome
In coming water temperatures
- Thread starter charlesdobson
- Start date
I wonder if the instantaneous water heater is simply not designed for UK temperatures as the average UK temperature, over a full year, is only about 10 degrees C which will be the average water temperature coming in.
Putting a heater in the barrel would be very inefficient, wasting most of it's energy to the atmosphere.
You could fit a supplementary water heater between the cold intake and the instantaneous heater.
Had thought of that , but it’s very hard to get a heater that will only bring the water temperature up to 15 degrees or there abouts ??
- Mar 14, 2005
- 19,165
- 4,365
- 50,935
Hi and welcome to the forum.
One of the forums members has already gone through a similar exercise, unfortunately I can't remember who it was, but I suspect he had a differnt heater in the caravan as he was looking to raise the external tank above 15C.
When posting technical questions it can help us a lot if you can provide make model and year of caravan, and similar information about any specific appliances your query may be about.
I suspect a fish tank heater and thermostat may be all you need. It would be best to have an adjustable thermostat. If you were to insulate your water barrel it would improve the efficiency, and of course would help prevent freezing.
One of the forums members has already gone through a similar exercise, unfortunately I can't remember who it was, but I suspect he had a differnt heater in the caravan as he was looking to raise the external tank above 15C.
When posting technical questions it can help us a lot if you can provide make model and year of caravan, and similar information about any specific appliances your query may be about.
I suspect a fish tank heater and thermostat may be all you need. It would be best to have an adjustable thermostat. If you were to insulate your water barrel it would improve the efficiency, and of course would help prevent freezing.
- Nov 11, 2009
- 25,256
- 9,165
- 50,935
It was Grey13 who put a lot of time into producing a system with additional heating so that he could enjoy longer showers. Last post was around time he was heading to italy with a new Jaguar F Pace tow car.
A search of his posts will highlight what he did. Look at “heater” by Grey13 and there are two detailed threads come up.
Last edited:
You can buy padded covers for the aquarol which might help. You'll need one with the hole for the water input.
Remember that increasing the barrel water temperature will increase the temperature of water from the cold taps.
Bags4Everthing at Ossett, W Yorks do some very good padded covers - including the pump pipe
Never tried it myself but a colleague used a suitably sized child anorak round the aquaroll with the sleeves for pipe accesses - might be worth a try if a charity shop or auction site can provide!
I think a previous suggestion of fitting an inline heater between the supply to my heater and the cold sounds like a good idea, would be easier to regulate, but it’s finding such an item is the trick!
That works to an extent, but after a while the heater throws up an air pressure fault with the water pump kicking in and out
Yes but they are designed to heat a fixed tank , not one that is constantly being topped up with cold water, from research it would take a 4kw to 6kw inline water heater to bring a constantly flowing tank from 10 degrees to 15 degrees, and couldn’t see many site hook ups withstand that amount of electricity
Thank you ,
To be honest this has only been a problem developed last week, and maybe it’s a sign to wrap up for the year , the caravan itself is getting cold at night , and we have had a good run this year despite all the storms. Caravan is home and will start clearing it out for the winter and get the cover on , and let it be a problem for next year when the season starts again
The air pressure fault is a sign the water is boiling , producing small pockets of steam causing the boiler pressure to jump up ( this effect is known as kettling and is a sign of low water pressure within the boiler) , if this is the case you may be be losing temperature in the pipes from the boiler to the taps , insulating them may help with a greater flow. An instantaneous water heater is designed to work with incoming water pressure of about 2 bar, external water pumps struggle to achieve when water is flowing. Fitting an internal pump would give greater pressure whilst water is flowing and not cause the water heater to struggle or kettle .
But the greater the flow , the cooler the water becomes, I’ve tried it with a 30psi pump and a 20 psi pump and the 20psi was the only one that flowed slow enough to let the water heat , yes 2 bar would be ok in a hot climate, but not in the uk , the instantaneous heater is brilliant, to have a proper shower in the caravan is amazing, but its downfall can be our water temperatures , and no matter what I do I can’t fix that , as for losing temperature, the shower is the farthest tap from the boiler and it always works perfect, why I’m baffled , I can have a 40 degree shower without a problem, just have to accept beyond October the water is too cold , as is the caravan for that matter
In an instantaneous heater the boiler fires the minute you open the tap , there is no storage in them , ie why they are called tankless heaters, you have a constant flow of hot water, not like the traditional boilers where you had to have an army shower of on, off , on off for the fear of running out of hot water
Facebook
Twitter