Truble with Truma UltraStore hot water heater

[pteehan]

Hello, I have a used Explorer Magnum which has just come into my possession and I'm having trouble figuring out the hot water.


I've hooked up the Aquaroll and the pump. The cold taps are working. When I turn on the hot tap, it sputters for a couple of minutes until eventually a steady stream of cold water comes out. My understanding is that the hot water tank is filling up during this period and once water flows from the hot tap it means the tank is full. At this point I turn off the taps and turn on the gas water heater. The control knob has a green LED and I can hear the sound of the flame lighting. I wait a while (30 minutes, an hour). I expect when I turn on the tap, hot water should come out? But what happens is another two minutes of sputtering and then cold water.


My best guess is that the water tank is filling up but not staying full. I've checked that yellow the drain valve is closed (flat, not sticking up). Any ideas how I can figure out what's going on and fix it? Thank you

 

[ProfJohnL]

Hello Pteehan, welcome to the forum.

You don't tell us teh exact age and model of caravan, but I will assume it has a Truma Ultrastore water heater

Your description of how the heater should work is correct. It should take between 20 to 30 mins to heat up from cold, and even after 5min you will get some warm water - good enough for washing hands.

However again I think your description of the way the heater is responding after heating does suggest the water is escaping from the heater, and the absence of a puddle points very strongly towards the failure of two non return valves that is allowing the content of the heater to drain back to the cold water container.

There should be an NRV in the cold water feed to the heater and there should be one on the cold water inlet into the caravan.

Look on page 9 of this, which describes where eth NRV's might be fitted,

https://caravanchronicles.files.wordpress.com/2013/03/truma-ultrastore-rapid-installation-instructions.pdf

Whether this solves your problem or not, I suspect the caravan is of an age that would benefit from having professionally checked with special attention to the function and safety of all the gas and electrical appliances.

Check out fully qualified mobile guys on the Approved Workshop Scheme.

Approved Touring Caravan & Motorhome Servicing in the UK

The Approved Workshop Scheme is the benchmark for motorhome and touring caravan servicing in the UK with fixed and mobile workshops nationwide.

www.approvedworkshops.co.uk

 

[Hutch]

Pteehan, is the heater actually on. Have you removed the outside vent cover, for the inlet , with this on the heater will flash up but will shut off again. Have a look and get back to the forum.

 

[Beachball]

Hi Pteehan welcome to the forum

 

[Gralay]

Hi Pteeham welcome to the forum I think with the ultrastore gas controller the green led indicates on(whether lit or not) the flame failure indicator is a very small led on the temperature selector (even if the flame has failed the green led is still on). It could also be a problem with the NRVs, you could try filling the system, and removing the suction pipe from aquaroll to see how much water comes out.

 

[pteehan]

Thanks for the advice. I'm pretty sure the heater itself is working as I can hear the gas turning on and off. The outside vent cover is off. I am going to order a new non return valve and see if that fixes it.

 

[ProfJohnL]

Thanks for the advice. I'm pretty sure the heater itself is working as I can hear the gas turning on and off. The outside vent cover is off. I am going to order a new non return valve and see if that fixes it.

Before buying an NRV do what Gralay suggests. It will prove if the NRV's are faulty.

 

[Thingy]

Is it pulling water straight from the barrel to the hot tap. Have you closed the drain tap?

 

[pteehan]

It was the non-return valve! I replaced it and the water tank is filling now. Thanks everyone