Technical Hot Water leak somewhere in the heater/electric compartment

[Nenagh52]

Truma 6. 4 years old
leaks a lot of water when hot taps are run.

When van is tilted over that side the water runs out underneath, when tilted the other way, runs out into the van.
On the photo below,

1. how does the fitting in the red box be opened?
2. The item in the blue box is the exhaust, is it glued in place?

I plan to disconnect the gas and take out the Combi
Any thoughts?
Thanks as always

 

[Communicator]

1. Water connector looks to be a John Guest or similar. I do not have these in my PVC, but if my old memory is correct push the red ring downwards, that is into the fitting. Connection can then be pulled apart.
2. Concentric exhaust (inner), and inlet (outer). I think that you will have to start with the large jubilee clip on the outer, abd pull that the outer tube fully back.

I have installation instructions dated 2004 for similar Combi. I may be able to post copy at more convenient time, but it may be possible to repair just your leaking connection. Connector could have worked loose due to faulty initial fitting. Perhaps even just push back together?

 

[HughJampton]

It will indeed be a "John Guest" type fitting, removal being as stated above. Note that there is sometimes a retaining clip between the red ring/collar and the fitting, which need to be pulled out before the ring can be pushed into the fitting (I can't see one on your 'photo, though) and even with the ring fully retracted they can then be somewhat difficult to remove by pulling. They come in different shapes and fittings, but the picture will give you some idea.

The fitting, whichever shape, contains a NRV allowing air in when you drain down. I don't know if this is where you think the water is coming from, but they are known to fail and aren't expensive/difficult to replace if you get the correct connections and geometry.

This picture of the fitting instructions might help with the (double) exhaust ducting:

 

[Nenagh52]

1. Water connector looks to be a John Guest or similar. I do not have these in my PVC, but if my old memory is correct push the red ring downwards, that is into the fitting. Connection can then be pulled apart.
2. Concentric exhaust (inner), and inlet (outer). I think that you will have to start with the large jubilee clip on the outer, abd pull that the outer tube fully back.

I have installation instructions dated 2004 for similar Combi. I may be able to post copy at more convenient time, but it may be possible to repair just your leaking connection. Connector could have worked loose due to faulty initial fitting. Perhaps even just push back together?

Thanks as always C!
On reading your post I went looking for the installation manual and found it so will explore it later, its the diesel fuel, vision but should work.
O have the dublin clip off as should be visible from the picture

It will indeed be a "John Guest" type fitting, removal being as stated above. Note that there is sometimes a retaining clip between the red ring/collar and the fitting, which need to be pulled out before the ring can be pushed into the fitting (I can't see one on your 'photo, though) and even with the ring fully retracted they can then be somewhat difficult to remove by pulling. They come in different shapes and fittings, but the picture will give you some idea.


View attachment 460079
The fitting, whichever shape, contains a NRV allowing air in when you drain down. I don't know if this is where you think the water is coming from, but they are known to fail and aren't expensive/difficult to replace if you get the correct connections and geometry.

This picture of the fitting instructions might help with the (double) exhaust ducting:

View attachment 460078

Thanks, I don't as yet know where the leak is from.
Need to get a helper to turn the water on and off while I have my head / camera down the hole as the flow rate is high
Thanks again

 

[Communicator]

It will indeed be a "John Guest" type fitting, removal being as stated above. Note that there is sometimes a retaining clip between the red ring/collar and the fitting, which need to be pulled out before the ring can be pushed into the fitting (I can't see one on your 'photo, though) and even with the ring fully retracted they can then be somewhat difficult to remove by pulling. They come in different shapes and fittings, but the picture will give you some idea.


View attachment 460079
The fitting, whichever shape, contains a NRV allowing air in when you drain down. I don't know if this is where you think the water is coming from, but they are known to fail and aren't expensive/difficult to replace if you get the correct connections and geometry.

This picture of the fitting instructions might help with the (double) exhaust ducting:

View attachment 460078

Thanks Hugh. Potentially saved me some time, as my manual is multi language paper copy, with diagrams and text on different pages.

 

[HughJampton]

Patently the leak could be just about anywhere until you locate it.

The NRV in the fitment you've highlighted does have a record of failing, however. The "aeration" side (smaller pipe - the other is the hot water outlet)) is conventionally routed through the floor via a pipe, so I suppose there's just a chance this isn't correctly routed/located..

 

[Nenagh52]

1. Water connector looks to be a John Guest or similar. I do not have these in my PVC, but if my old memory is correct push the red ring downwards, that is into the fitting. Connection can then be pulled apart.
2. Concentric exhaust (inner), and inlet (outer). I think that you will have to start with the large jubilee clip on the outer, abd pull that the outer tube fully back.

I have installation instructions dated 2004 for similar Combi. I may be able to post copy at more convenient time, but it may be possible to repair just your leaking connection. Connector could have worked loose due to faulty initial fitting. Perhaps even just push back together?

Thanks as always C!
On reading your post I went looking for the installation manual and found it so will explore it later, its the diesel fuel, vision but should work.
O have the dublin clip off as should be visible from the picture

Patently the leak could be just about anywhere until you locate it.

The NRV in the fitment you've highlighted does have a record of failing, however. The "aeration" side (smaller pipe - the other is the hot water outlet)) is conventionally routed through the floor via a pipe, so I suppose there's just a chance this isn't correctly routed/located..

Am going to see if I can isolate the CW supply to the Combi before I go any further

 

[Googlebot]

Has it been subject to frost? The tanks can split if not drained.

You might need to cut a bit off the exhaust to have a sound surface to reseal back on. No issue as they are normally longer than needed.

Dry everything then use talcum powder to try and see where the water is tracking. It might not be fresh water, on mine the waste was leaking by the boiler.

Use some silicone grease when you reassemble the water fittings. Helps the O rings last much longer,

 

[Nenagh52]

Has it been subject to frost? The tanks can split if not drained.

You might need to cut a bit off the exhaust to have a sound surface to reseal back on. No issue as they are normally longer than needed.

Dry everything then use talcum powder to try and see where the water is tracking. It might not be fresh water, on mine the waste was leaking by the boiler.

Use some silicone grease when you reassemble the water fittings. Helps the O rings last much longer,

Thanks, pretty certain its the hot water side when the pump turns on, the other clue that it could be the tank is that when I turn on the hot tap it blows air initially so I suspect its the tank that is leaking.
Will try isolate the cold supply first before removing the Combi

 

[Googlebot]

Thanks, pretty certain its the hot water side when the pump turns on, the other clue that it could be the tank is that when I turn on the hot tap it blows air initially so I suspect its the tank that is leaking.
Will try isolate the cold supply first before removing the Combi

It will blow air first if the non return valve is before the leak. It might be coming from the frost valve but that’s normally easily accessible so you can reset it.

Fingers crossed for you, they aren’t cheap if the tank is split. :-(

Let us all know what you find.

 

[Nenagh52]

Am a bit puzzled by what follows:
Took off the clear tubing "overflow" tube from the John guest and the HW tank emptied through the frost valve
I suspect the non return valve prevented that from happening.
I will run a fine wire down the overflow tube to see is it blocked

 

[HughJampton]

If it's the fitting you've highlighted, the tube isn't an overflow, it's an aeration tube. The NRV is designed to prevent water escaping when full/under pressure, but allow air in as the pressure drops on emptying, ensuring full evacuation. Under normal circumstances water shouldn't escape there, but might with a failed NRV. It should exit through the floor to avoid issues when there is a failure.

It's difficult to confirm, but if the boiler dumped more water when the tube was removed then it seem at least possible that the tube was blocked, or the NRV was stuck and movement has freed it, thereby letting more air in and prompting the dumping.j

 

[Googlebot]

If it's the fitting you've highlighted, the tube isn't an overflow, it's an aeration tube. The NRV is designed to prevent water escaping when full/under pressure, but allow air in as the pressure drops on emptying, ensuring full evacuation. Under normal circumstances water shouldn't escape there, but might with a failed NRV. It should exit through the floor to avoid issues when there is a failure.

View attachment 460147

It's difficult to confirm, but if the boiler dumped more water when the tube was removed then it seem at least possible that the tube was blocked, or the NRV was stuck and movement has freed it, thereby letting more air in and prompting the dumping.j

They are easy to change and not that expensive. I would swap it out, sounds like it is sticking.

 

[Nenagh52]

So this unit seems faulty
The push button wont stay in and I don't know if it's the cold or faulty. will heat it with a hairdryer later and see.
It is serviceable or do I need a new one.
Thanks

 

[Googlebot]

So this unit seems faulty
The push button wont stay in and I don't know if it's the cold or faulty. will heat it with a hairdryer later and see.
It is serviceable or do I need a new one.
Thanks

They automatically open when cold to protect the tank. The outlet should exit below the vehicle.

It’s probably too cold as they are normally quite reliable. Think they dump at 2 degrees Celsius. A hairdryer probably won’t sort it, they need to be warm all over. I would put the heating on for a while and then check. They are able to have the heating on and the tank empty.

The hairdryer will work eventually but you might need to leave it on for a while.

 

[Communicator]

They automatically open when cold to protect the tank. The outlet should exit below the vehicle.

It’s probably too cold as they are normally quite reliable. Think they dump at 2 degrees Celsius. A hairdryer probably won’t sort it, they need to be warm all over. I would put the heating on for a while and then check. They are able to have the heating on and the tank empty.

The hairdryer will work eventually but you might need to leave it on for a while.

Yes, I have read aout such valves dumping all water overnight, at temperatures above freezing. The temperature of 4C comes to mind. The valve on my PVC is the manual version, which keeps it simple.

 

[HughJampton]

That particular model of frost protection valve opens at c3°, but won't close again until c7°. I can vouch for the fact that raising the temperature to the latter when it's been cold enough to open it takes some time with a hairdryer or fan heater.

The units are pretty reliable, so I suspect it isn't warm enough to reset.

 

[Nenagh52]

That particular model of frost protection valve opens at c3°, but won't close again until c7°. I can vouch for the fact that raising the temperature to the latter when it's been cold enough to open it takes some time with a hairdryer or fan heater.

The units are pretty reliable, so I suspect it isn't warm enough to reset.

Thanks, its 3 here at the moment.
May need a hot water bottle!