[dazmond]

The black plastic mixer valve blew off the side of my heater on my last job of the day spewing hot water all over the back of my van and this spring and plastic came out too spruce....

I'm not sure which order it goes back into the mixer valve.....also there was a little black plastic stud with a metal pin thingy in the middle 🤔

I can't seem to find the right information to put this back together correctly?I thought you might be able to help!

Cheers in advance

[dazmond]

Sussed it.

Thin plastic end goes into the heat exchanger hole(with spring over it)and the black plastic stud (with metal pin) goes into the end mixer valve then screw it on.

Just fired up it up and heater working fine as usual.

Do you know why it blew off in the first place spruce?there's not much thread on the valve,maybe it's worked loose with the vibration of driving every day?

[Ched]

The white plastic bit looks damaged. Make sure none of the broken bits are inside the heater.
If it's blown off once then it probably will fail again. Think of a backup for tomorrow should it fail, i.e can you bypass the heater so you can finish your work? Can you just go home and have a couple of days off while the new parts arrive? Is there a canal boat repair place nearby that might do webasto spares?
See if you can find an exploded view of the heater and see if you can work out why it failed - ie. has a pressure relief valve got stuck with the frost etc.
Look at alternatives for the problem - is your controller dead ending correctly and not over pressurising the heater, any possibility of ice causing a blockage.

Don't just assume you have fixed it!

[dazmond]

The white plastic bit looks damaged. Make sure none of the broken bits are inside the heater.
If it's blown off once then it probably will fail again. Think of a backup for tomorrow should it fail, i.e can you bypass the heater so you can finish your work? Can you just go home and have a couple of days off while the new parts arrive? Is there a canal boat repair place nearby that might do webasto spares?
See if you can find an exploded view of the heater and see if you can work out why it failed - ie. has a pressure relief valve got stuck with the frost etc.
Look at alternatives for the problem - is your controller dead ending correctly and not over pressurising the heater, any possibility of ice causing a blockage.

Don't just assume you have fixed it!

Ched I've had it running for 30 mins tonight and heaters  fine.its happened before a few years ago but I forgot how it fitted together.🙂

I've tightened up the nut in the middle of the end valve too...its probably just worked loose over the years with the vibration.

[DJW]

Looks like a chunk of plastic has gone missing to me. I would spend some Christmas tips and buy a new one. Maybe Loctite the screw thread on the cap of the new one.

[Spruce]

TBH I've never taken one apart.

I can't think why it would blow off in the first place, as the control k nob has a stop lug which only allows the k nob to rotate once.

Looking at the plastic component, I would suggest as Ched that you replace the whole mixer valve.

https://www.butlertechnik.com/webasto-mixer-valve-kit-p1793

https://www.jpcdirect.com/product/isotemp-mixing-valve-kit/

Running the heater on its own won't help you. You need the heat exchanger under pressure with the wfp pump.

[֍Winp®oClean֍]

(Sucks through teeth) 'looks expensive Daz'. I see a 4 Star hotel next year!!🤣

[Spruce]

The white plastic bit looks damaged. Make sure none of the broken bits are inside the heater.
If it's blown off once then it probably will fail again. Think of a backup for tomorrow should it fail, i.e can you bypass the heater so you can finish your work? Can you just go home and have a couple of days off while the new parts arrive? Is there a canal boat repair place nearby that might do webasto spares?
See if you can find an exploded view of the heater and see if you can work out why it failed - ie. has a pressure relief valve got stuck with the frost etc.
Look at alternatives for the problem - is your controller dead ending correctly and not over pressurising the heater, any possibility of ice causing a blockage.

Don't just assume you have fixed it!

Last year, no one had stock of those mixer valves; not even the go-to supplier in Turkey.

The solution was a standard mixer valve, which is more readily available from plumbing outlets. These are fine for canal boats as they have a much lower hot water temperature. 46 degrees is the hottest you can get, where we need a much higher temperature output at around 60 degrees C. These are usually mounted on the hot water cylinder in a canal boat and once adjusted, isn't usually changed again.

https://www.butlertechnik.com/eberspacher-or-webasto-thermostatic-mixer-valve-tmv-kit-for-3-4-thread-plate-heat-exchangers-p3453

The other issue is the orientation of the adjuster k nob. On our systems, the heat exchanger is inside the heater boxing with the control k nob outside so we can easily adjust the output temperature. If we use one of the Pegler mixer valves, we need to remove the front panel of the heater to make that adjustment. Is it the end of the world? No, because I can't remember when I last adjusted the output temperature. But still, its not ideal.

One of the other issues is pipe orientation inside the heater box. Grippatank do pack their heaters very tightly, so making piping modifications could well mean modifications to the heater hoses.

 

 

[Spruce]

I've put this up on the other forum.

Here is the part Daz must order;

https://www.jpcdirect.com/product/isotemp-thermostat-mixing-valve/

[Jonny 87]

One of mine popped off years ago when I was messing around with the adjustment of the valve. You can tweak it past the stopper to give more or less heat. I think I was trying to reduce my heat output.

I turned the valve down and it came off in my hand.

Not sure if that helps, but if you’ve adjusted it recently then it could be the problem.

[dazmond]

I've put this up on the other forum.

Here is the part Daz must order;

https://www.jpcdirect.com/product/isotemp-thermostat-mixing-valve/

Thanks spruce your a star!👍🙂

I've just ordered it.came to £75 including vat and delivery.

I've currently only got 40c water(coiled up hose ).

It's as if the heater is in constant half heat mode....no matter what I do with the mixer valve.it either comes off the side of the heater or just stays in half heat mode!

[robert mitchell]

Mine doesnt have a mixer valve and to be honest , i dont really see the point .

Been running without one for years and never felt the need to adjust the temperature , i find that the colder it gets , the cooler the water coming out of the jets , pretty much self regulating , never cracked a window yet ........touch wood!

[Splash & dash]

I've put this up on the other forum.

Here is the part Daz must order;

https://www.jpcdirect.com/product/isotemp-thermostat-mixing-valve/

The bit that can easily come out is the bit behind the black nob   if you take that nob   off there is a black plastic threaded insert that screws in and out to adjust the temperature, when I had trouble with one of mine years ago you couldn’t buy just the black threaded bit had to by the whole valve at around £100 I think it was.  The plastic goes hard and brittle with the constant heat and breaks up .

[Splash & dash]

Mine doesnt have a mixer valve and to be honest , i dont really see the point .

Been running without one for years and never felt the need to adjust the temperature , i find that the colder it gets , the cooler the water coming out of the jets , pretty much self regulating , never cracked a window yet ........touch wood!

We turn the heat down in summer as it gets that hot you can hold the hose  winter time it’s fine

[dazmond]

Mine doesnt have a mixer valve and to be honest , i dont really see the point .

Been running without one for years and never felt the need to adjust the temperature , i find that the colder it gets , the cooler the water coming out of the jets , pretty much self regulating , never cracked a window yet ........touch wood!

Trust me mate...I wish mine didn't have one.i never touch it usually but it just blew off and I can't get it to run on full heat now....

New mixer valve coming tomorrow.i think I'll just try and change the mixer end numpty and the spring and plastic plunger first and see if that cures it....I don't feel confident in changing the whole part tbh.....

[robert mitchell]

Mine doesnt have a mixer valve and to be honest , i dont really see the point .

Been running without one for years and never felt the need to adjust the temperature , i find that the colder it gets , the cooler the water coming out of the jets , pretty much self regulating , never cracked a window yet ........touch wood!

We turn the heat down in summer as it gets that hot you can hold the hose  winter time it’s fine

It does get rather hot at times and that would only bother me if i had employees ,

[robert mitchell]

Mine doesnt have a mixer valve and to be honest , i dont really see the point .

Been running without one for years and never felt the need to adjust the temperature , i find that the colder it gets , the cooler the water coming out of the jets , pretty much self regulating , never cracked a window yet ........touch wood!

Trust me mate...I wish mine didn't have one.i never touch it usually but it just blew off and I can't get it to run on full heat now....

New mixer valve coming tomorrow.i think I'll just try and change the mixer end numpty and the spring and plastic plunger first and see if that cures it....I don't feel confident in changing the whole part tbh.....

Should be very easy to change mate , i would bypass it myself though , save hassle in the future.

[Spruce]

Mine doesnt have a mixer valve and to be honest , i dont really see the point .

Been running without one for years and never felt the need to adjust the temperature , i find that the colder it gets , the cooler the water coming out of the jets , pretty much self regulating , never cracked a window yet ........touch wood!

Trust me mate...I wish mine didn't have one.i never touch it usually but it just blew off and I can't get it to run on full heat now....

New mixer valve coming tomorrow.i think I'll just try and change the mixer end numpty and the spring and plastic plunger first and see if that cures it....I don't feel confident in changing the whole part tbh.....

As Splash and Dash says, the further you wind the retainer in, the greater the temperature change. I wouldn't touch the valve innards tbh as you will mess up the temperature settings. I would replace it as a unit. Just remove it step by step. I suggest you order some Loctite 572 which is a good thread sealer. Once assembled, you can run the heater, but not the pump side. You must wait until the thread sealer hardens.

If the threads on the housing are damaged, then you are going to repeat the failure by just replacing the 'cartridge.'

[dazmond]

Mine doesnt have a mixer valve and to be honest , i dont really see the point .

Been running without one for years and never felt the need to adjust the temperature , i find that the colder it gets , the cooler the water coming out of the jets , pretty much self regulating , never cracked a window yet ........touch wood!

Trust me mate...I wish mine didn't have one.i never touch it usually but it just blew off and I can't get it to run on full heat now....

New mixer valve coming tomorrow.i think I'll just try and change the mixer end numpty and the spring and plastic plunger first and see if that cures it....I don't feel confident in changing the whole part tbh.....

As Splash and Dash says, the further you wind the retainer in, the greater the temperature change. I wouldn't touch the valve innards tbh as you will mess up the temperature settings. I would replace it as a unit. Just remove it step by step. I suggest you order some Loctite 572 which is a good thread sealer. Once assembled, you can run the heater, but not the pump side. You must wait until the thread sealer hardens.

If the threads on the housing are damaged, then you are going to repeat the failure by just replacing the 'cartridge.'

I think your right spruce.its only 3 bits that need screwing together.ill just replace like with like.

I think I'll leave it until the xmas break to replace it and order some loctite 572 tomorrow.it looks like there's loads of this already on the threads on the old mixer valve.

[dazmond]

Loads of loctite on the original valve!