Truma Combi Heater

[starvin marvin]

I have an IH Motorcamper with one of the above heaters. I'm trying to find the drain down valve and currently can't see anything thats obviously a drain down point. Can anyone help?

 

Thanks

[Robinhood]

There is (AFAIK - unless there are variants) no valve on the unit itself.

 

It is usually fitted remotely, on the end of a length of hose, and may be an automatic (dump) valve that opens at 5 degrees C (with a permanent 12V feed), or it may have been fitted with a manual valve.

 

Likely to be hidden away in a cupboard somewhere.

 

Best thing is to trace the pipework from the unit untill you find it. (If this is difficult, look for the hose outlet underneath the vehicle, which may give you some view as to where it is - my guess is that the valve will be near the end of the run).

[davenewellhome]

First port of call should be the owner's handbook which should give you drain down procedures and where to find the relevant valves etc. Failing that why not phone IH and ask them?

 

D.

[Derek Uzzell]

Robinhood's advice is essentially correct.

 

A Truma C-Series (Combi) heater has no integral drain-valve. Draining the appliance of water is carried out by opening a drain-valve (usually electrically-powered, but occasionally manually operated) completely separate from the heater, followed by opening a sink/shower/wash-basin hot 'tap'.

 

The drain-valve will have been inserted in the water-hose leading from the motorhome's fresh-water pump to the water-inlet at the base of the heater. If a diaphragm-type water-pump has been used, then you might well find the pump and drain-valve reasonably close to the heater. If the water-pump is of the 'submerged' type (ie. the pump is inside the fresh-water tank), then the drain-valve may be located further afield. Wherever the valve is, for effective draining it needs to be positioned below the level of the heater's water-inlet.

 

So, to find the drain-valve, first identify the hose that connects to the water-inlet at the bottom of the heater, then trace that hose's route back towards the motorhome's fresh-water tank. If you arrive at the water-pump, or the water tank, and still haven't found a drain-valve, then you've got a problem! However, I very much doubt IH would forget to fit such a valve.

 

Operation of a C-series heater is fairly complex and motorhome manufacturers tend not to provide detailed instructions about it in their handbooks, relying instead on the information given in Truma's own documentation. Handbooks also tend to be generic, so model-specific details of where things like drain-valves are may well be omitted. My Hobby's handbook describes how to drain the Truma appliance and provides a drawing of the (electric) drain-valve, but it doesn't tell the Hobby owner where the drain-valve is.

 

If you haven't already got Truma's Operating/Installation leaflets for your particular model of C-Series heater, you can download those documents from www.truma.com or e-mail Truma(UK) on technical@trumauk.com and ask them to send you hard-copy versions.