Truma combi frost valve.

Obanboy666

Obanboy666

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Before heading out after lunch today I filled up with water then went to close the Truma drain valve to find the frost protection had activated and wouldn't reset.
Temperature obviously to low so I put the Truma on heating only which you can do with no water in the boiler and within 20 minutes I could reset the valve. I then filled the boiler bleeding the taps etc.
I've heard mention that people fasten the button in on the valve with something or other, what's this all about as once the boiler is up to temp the temp shouldn't drop to activate the frost valve.
 
If it is the button type that pops down to empty the water, then put a peg on it to stop it popping down, but remember to take if off if the water starts to freeze
 
I use the clothes peg method to enable me to fill the boiler when the valve has operated because of low temperature,you just have remember to remove it when the tank is up to temperature.If on a site with hook up then I leave the water heating on electric all the time,if no hook up is available then I just leave it on gas-40°.Once it's up to temperature it uses a surprisingly small amount of gas to keep it there.
 
Use a clothes peg...annoying that the water dumps at about 3 deg C, and you can't reset till temp reaches approx 8 deg C. I know it's there to protect the expensive boiler from frost damage, but once you've got a fair bit of experience under your belt, you can work round it.

Allen
 
Bentleys came with the manual valve already fitted in replacement for the automatic ones, with a suitable warning. I think that the manual valve is a better idea.
 
The auto dump valve was changed by Truma around 2009, so with a newer motorhome the peg solution won't work and I haven't managed to fathom out how to hold the blue knob in on the new system. I got so fed up with it that I simply replaced the auto dump valve with a simple (and cheap) manual valve. Much better but you must remember to leave it open if frost is likely and you're not using the van.
Tony
 
A plastic cable tie looped from the back to the front over the valve to hold the button (B) in works in cold weather - just flip the cable tie up and off when not required - put it back when required.

Tap.jpg
 
Keithchesterfield said:
A plastic cable tie looped from the back to the front over the valve to hold the button (B) in works in cold weather - just flip the cable tie up and off when not required - put it back when required.

View attachment 48680
Click to expand...

That's the one i have, think I'll just leave as is.
I always dump the water when I come home in winter and when out and about boiler always on so will always be ok.
If like this morning and it won't reset to allow me to fill the boiler I'll just put it on heating only which will warm it up and reset the dump valve.
 
Nuisance

Not only does the the valve dump your water when the temp drops, it dumps it when the battery voltage drops below 11v I think it is and dumps it all. If you leave on hook up its OK as long as you are not on the Italian Arsilicii cambus wiring system which only lets you leave hook up on for 2 days a month or the panels burn out. If you are not on hook up the valve coil is active all the time so after a bit of time the battery power drops and it dumps it anyway. Also on my system which is a load of expensive junk, when travelling and you are on 12v and you pull up and go for a meal or something and forget to change to gas the fridge stays on battery power and that really takes the voltage down fast. You come back to the van and the car park is flooded with your fresh water dumped again. I put a crocodile clip on it now. Its going to Wales soon for an expensive electrics overhaul and hope to sort a better system out.
.... Tom ....
 
stonedaddy said:
Not only does the the valve dump your water when the temp drops, it dumps it when the battery voltage drops below 11v I think it is and dumps it all. If you leave on hook up its OK as long as you are not on the Italian Arsilicii cambus wiring system which only lets you leave hook up on for 2 days a month or the panels burn out. If you are not on hook up the valve coil is active all the time so after a bit of time the battery power drops and it dumps it anyway. Also on my system which is a load of expensive junk, when travelling and you are on 12v and you pull up and go for a meal or something and forget to change to gas the fridge stays on battery power and that really takes the voltage down fast. You come back to the vanŵ and the car park is flooded with your fresh water dumped again. I put a crocodile clip on it now. Its going to Wales soon for an expensive electrics overhaul and hope to sort a better system out.
.... Tom ....
Click to expand...

Interesting, my manual states it's currentless and looking at it there is no wiring going to it.
If there is an electrical connection to it I've never had the batteries less than 12 volt and hopefully never will as they are on ehu 24/7 when parked up at home and if there was a chance of the voltage dropping low I would start my genny up. Probably do that tonight as my solar panel isn't doing much at present.
IMG_0638.PNG
 
On our last Hymer, I bypassed the valve with a short length of rigid pipe, re connected it when we sold the van.
 
The old style black valve has a groove around the valve stem. A suitably shaped piece of 2mm Plastic does the job.
 
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