# Trumatic Combi C3400 Problems



## 105158 (Jun 13, 2007)

Can anybody please help with a problem I have refilling my Trumatic C3400 on a Pilote motorhome? I have owned it since last summer and drained it down over the winter. I have not refilled from empty before and can't seem to reset the the frost protection switch. When pushing the yellow button, it will not stay down. The Truma tank must be filling as water is draining from the dump hose outside. When I hold it down the water stops flowing, but it won't stay in this position. I can't get water from the hot taps (sink and bath) 
but cold is flowing nicely. The rocker switch next to the yellow button is at the 
"I" position as in the manual. 
Any suggestions would be appreciated. 

jonesthetaxi


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## 104477 (May 13, 2007)

Have you got a swith like this one (fitted to a C6002 Truma)?


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## Spacerunner (Mar 18, 2006)

Try firing it up. The increase in temperature should allow the safety valve to stay closed.


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## sergeant (Jun 7, 2006)

Hi Jones, Dont forget you need the 12v switched on for the valve to hold shut, Steve


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## chrisgog (May 17, 2005)

Ours would not stay shut until temperature rose in and out of the van. It was about 5 degrees outside at the time.
Check the temperature and maybe put a heater in van to warm up the air
Chris


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## 105158 (Jun 13, 2007)

Many thanks to rapidorob, spacerunner, sergeant, & chrisgog for amazingly quick replies.
In turn: No rapidorob my switch is a large yellow button that you push down to reset. Spacerunner, I have tried to fire up the water heater but it cuts out after a minute or so. Sergeant I have the 12volt panel on but thanks anyway.
Chrisgog, sounds like a possible although I did play a hair drier on it after reading about this trick on these forums. No luck so far, will try again tomorrow perhaps with the heater in the van.
My thanks again to you all, will post here if I solve it.

You people are amazing for the help you give to others.
Makes me feel humble.


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## JockandRita (Jun 1, 2005)

rapidorob said:


> Have you got a swith like this one (fitted to a C6002 Truma)?


Hi *Rob*,

We have the same switch as yours on our C3402. Perhaps Jonesthetaxi has an earlier model.

*Jonesthetaxi*,

I seem to remember that Vicdicdoc had the same yellow button on his Truma system, and I think that he replaced or bypassed it due to the problems he was having. 
See Here

HTH,

Jock.


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## twizz (Mar 16, 2006)

We have the same type of button as rapidorob's photo. We were told by our supplier to stick a piece of metal through the hole in the knob and put a peg underneath to stop the button being able to go down, if we want to use below 8 degrees without the heating on in the van. Obviously that removes the safety aspect of the system so we have to remember to dismantle before leaving the van unused in cold weather (possibly playing with fire!). Also, of course, there may not be a hole or way of wedging the button up on your version.


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## geordie01 (Apr 20, 2006)

why not remove the valve and fit a manual valve in its place. u wil just have to remember to drain it when there is a chance frost


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## 105158 (Jun 13, 2007)

Hi everyone,
Jonesthetaxi again,
Have had limited success today with the above problem. Got the boiler to fire up. Seemed the gas pipes were empty at some point. Managed to keep the frost protection button down by holding it down whilst the water was heating up. Stayed in that position for a while but couldn't get any water from the hot taps apart from the odd splutter here and there. The thermostat cut in when the tank reached temperature but still no hot water flowing. Even got the missus to suck on the bathroom tap only to get a mouthful of water and not much else. Just about to take a break when I noticed the water coming out of the dump hose outside. The switch has popped up again.
Anybody know how to bleed the air out of the pipes?


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## JockandRita (Jun 1, 2005)

jonesthetaxi said:


> Hi everyone,
> Jonesthetaxi again,
> Have had limited success today with the above problem. Got the boiler to fire up. Seemed the gas pipes were empty at some point. Managed to keep the frost protection button down by holding it down whilst the water was heating up. Stayed in that position for a while but couldn't get any water from the hot taps apart from the odd splutter here and there. The thermostat cut in when the tank reached temperature but still no hot water flowing. Even got the missus to suck on the bathroom tap only to get a mouthful of water and not much else. Just about to take a break when I noticed the water coming out of the dump hose outside. The switch has popped up again.
> Anybody know how to bleed the air out of the pipes?


Hi J...T...T..., :wink:

Open your hot taps and have the pump switched on. Air will eventually be purged from the system by the flow of water. Believe me when I say, that it can take some time from empty. Once the hot water tank fills from the cold tank, the lines will begin to fill. Be careful not to open a tap that you cannot observe, ie, don't leave unattended.

As you have used up your last post, you'll have to sign up to keep in touch, or to gain further advice. 
I apologise in advance, but I am not prepared to make my e-mail address public on the www, but would like to continue to help you.

TTFN,

Jock.


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## chrisgog (May 17, 2005)

Yes, To reiterate. You MUST open the hot water taps full then turn on the pump. It will take a good couple of minutes to then fill the hot water tank from the cold water supply. You will get spluttering then after a while the water spits out and starts to run. It will take 12 litres out of your cold water tank then so look at the water level in your tank and you will see it going down. 

When it is full THEN you can turn hot water on.

If it is too cold it will dump the water but not from your cold tank...only the 12 litres you have in the hot tank.

A peg is ok if you can be trusted but I never would personally. Why did they put it there if it wasn't meant to dump at low temperatures.

Sign up Jones the taxi as it is worth the free advice for a tenner
Hope you have success
chris


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