Hi can you help a dummy? There is a constant water leak from the DHW vale at the diaphragm housing. Both the diverter and DHW diaphragms have been replaced. When there is flow/demand on the system the leak stops. Both the plungers are lifting the micro-switches OK. Pressure in the line naturally drops off but leaks when topped up even slightly. The system is 10 year old. Any ideas its driving us crazy - buckets of water every day. Cheers, Scott
Ocean Alpha 240P DHW valve leak
- Thread starter scott2442
- Start date
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You have not explained your problem very clearly.
The two pins which operate microswitches both run through gland seals and these need to be replaced if leaking.
The one at the front is mains water and are more of a nuisence than a danger.
The system flow switch on the top further back is system water but far less often lean. That will cause the system water pressure to go down and frequent toping up causes dirt to be produced in the system an dshould be dealt with quickly.
Anyone competent would have changed any leaking seals when replacing diaphragms.
Tony
The two pins which operate microswitches both run through gland seals and these need to be replaced if leaking.
The one at the front is mains water and are more of a nuisence than a danger.
The system flow switch on the top further back is system water but far less often lean. That will cause the system water pressure to go down and frequent toping up causes dirt to be produced in the system an dshould be dealt with quickly.
Anyone competent would have changed any leaking seals when replacing diaphragms.
Tony
Hi, sorry. The water is leaking from the front cover of the DHW not from the centre but the bottom of the diaphragm housing. The Diaphragm seems intact and the housing appears undamaged. It appears to me that pressure is forcing its way passed the seal.
When the heating system is running then the leak reduces to virtually nothing but when heating is off the leak is constant. Could the likely cause be internal seals of the diverter valve?
Many Thanks, Scott
When the heating system is running then the leak reduces to virtually nothing but when heating is off the leak is constant. Could the likely cause be internal seals of the diverter valve?
Many Thanks, Scott
I suspect the leak is actually from behind the diaphragm assembly and running down the back to make it look as if the diaphragm is leaking.
It might be CH water or mains water.
Does the CH pressure go down?
What happens when the DHW in is turned off? Does that stop the leak?
Have you examined the back of the housing?
Tony
It might be CH water or mains water.
Does the CH pressure go down?
What happens when the DHW in is turned off? Does that stop the leak?
Have you examined the back of the housing?
Tony
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Hi, I agree that it is probably leaking from behind the diaphragm. When the water is off the pressure in the heating loop gradually drops away to nothing. As soon as there is pressure back into the filling loop then the leak begins. When the system is delivering i.e. the heating system is on demand then the leak fades away but comes back as soon as the heating is off. I also note a gradual increase in the line pressure during operation.
I somehow feel that it may be seals within the diverter valve but wonder whether it could be heat exchanger failed. I have inspected the housing which appears to be sound. I previously found the primary flow valve had perished but this was replaced.
Many Thanks, Scott
I somehow feel that it may be seals within the diverter valve but wonder whether it could be heat exchanger failed. I have inspected the housing which appears to be sound. I previously found the primary flow valve had perished but this was replaced.
Many Thanks, Scott
I expect that it is the front seal in the manifold section of the diverter valve which is leaking and running down the back of the diaphragm section.
If you are clever and a glutton for punishment you can dismantle the whole diverter and replace every seal.
Commercially thats not viable and we would always replace the whole valve if the manifold is sticking or leaking. We do replace the diaphragm on its own though.
Your plate heat exchanger is fine.
Tony
If you are clever and a glutton for punishment you can dismantle the whole diverter and replace every seal.
Commercially thats not viable and we would always replace the whole valve if the manifold is sticking or leaking. We do replace the diaphragm on its own though.
Your plate heat exchanger is fine.
Tony
I have observed this fault/leak many times before. Luckily I have cured it by just replacing, or in one case adding, a new 'o' ring to the back pin on the front housing assembly.
This is the minute 'o' ring about 1mm diameter.
This is the minute 'o' ring about 1mm diameter.
It does sound like a diverter seal, suppose from a commercial view point replacing the diverter would be a better option although it could be a gamble that one seal may be all that is needed - naturally replacing them all anyway.
Not too sure where the back pin on the front housing assembly refers, is this inside the diverter valve.
Cheers, Scott
Not too sure where the back pin on the front housing assembly refers, is this inside the diverter valve.
Cheers, Scott
hi there,
These old style permanent pilot boilers are very inefficient, wouldnt it be worthwhile investing cash in a new condensing boiler, we currently manage over 40 properties and are upgrading all the permanent pilot boilers to the latest models, if you can do all the repairs yourself it may be cost effective to stick with your oldun but i know what i would be doing
steve
These old style permanent pilot boilers are very inefficient, wouldnt it be worthwhile investing cash in a new condensing boiler, we currently manage over 40 properties and are upgrading all the permanent pilot boilers to the latest models, if you can do all the repairs yourself it may be cost effective to stick with your oldun but i know what i would be doing
steve
That is the DHW seal on the back of the diaphragm unit.
However in this case its the front seal in the manifuld section which is leaking.
I would also change any seals in then diaphragm unit. Its only the manifold section which I would replace as a unit. This is because its time consuming to dismantle and clean and not something to be doing on a clients premises. Its more cost effective to replace it with a new one.
Tony
Hi, the leak is from the back of diaphragm unit of the DHW valve, it is emitting from the spare securing screw hole. When you say the the front seal of the manifold block I am confused as where you mean. The diverter/3 way valve has: DHW flow valve, Primary flow valve, by pass section and diverter section.
Or are you referring to the main DHW inlet manifold/PRV unit.
Would the seal you refer be in a diverter seal kit, I have just seen a parts list which I think may be the seals you may be referring; item number 120, naturally this item is not listed as available, would this be the kit I need.
Cheers, Scott
Or are you referring to the main DHW inlet manifold/PRV unit.
Would the seal you refer be in a diverter seal kit, I have just seen a parts list which I think may be the seals you may be referring; item number 120, naturally this item is not listed as available, would this be the kit I need.
Cheers, Scott
Hi if you turn off all valves under boiler ie flow,return & cold mains water in plus electrics and drain boiler.
Remove front micro switch, undo both small pipes from top of diapragm housing, lossen both retaining screws at rear of diapragm housing the housing will come off and you will see the pin coming from the centre of the diverter valve, if when it leaks you loose system pressure your leak will be coming from pin, if you remove the two retaining screws for the domestic hot water diapragm and get a wrench on the front section of the diverter valve you can remove it, you can buy a new section to stop this leak it does not have any replaceable O rings.
Remove front micro switch, undo both small pipes from top of diapragm housing, lossen both retaining screws at rear of diapragm housing the housing will come off and you will see the pin coming from the centre of the diverter valve, if when it leaks you loose system pressure your leak will be coming from pin, if you remove the two retaining screws for the domestic hot water diapragm and get a wrench on the front section of the diverter valve you can remove it, you can buy a new section to stop this leak it does not have any replaceable O rings.
If Agile is right diagnostically buy a new dhw flow valve part 562950
the Baxi part is probably cheaper http://www.ezypart.co.uk/parts/part_id__2241
There is a service kit for the primary section and another for the dhw section but I don't recall part numbers phone Alpha ask help desk. As Tony says not easy. Here is the primary service section on ebay 260253823822
He might have a dhw flow valve section service kit for you if you ask
Believe it or not all I had as stock for that generation of alpha was the various servicekits the next generation I had both service kits and complete assemblies. In that next generation 9times out of 10 service kit was all that was required and actually easy to implement.
The one you have took me about an hour to completely overhaul from arriving at the house to driving away which is a very long time.
You have to thoroughly clean the insides of the manifolds.
You do see the primary section of this diverter valve on ebay here is one item no 360066839150
As for energy efficiency advice above your boiler is not a permanent pilot model. The only problems it ever has are the ones you describe if you bought new valves as Tony advised you would probably get another 10 years after which we will all be burning logs as there won't be any gas.. Actually I expect to be burning logs quite soon at todays gas prices. And i am going to knit my own solar.
The cost and management accountant in me does not buy the replace a band d with band a boiler argument. Anyone who falls for it is ignorant of capital project decision analysis.
the Baxi part is probably cheaper http://www.ezypart.co.uk/parts/part_id__2241
There is a service kit for the primary section and another for the dhw section but I don't recall part numbers phone Alpha ask help desk. As Tony says not easy. Here is the primary service section on ebay 260253823822
He might have a dhw flow valve section service kit for you if you ask
Believe it or not all I had as stock for that generation of alpha was the various servicekits the next generation I had both service kits and complete assemblies. In that next generation 9times out of 10 service kit was all that was required and actually easy to implement.
The one you have took me about an hour to completely overhaul from arriving at the house to driving away which is a very long time.
You have to thoroughly clean the insides of the manifolds.
You do see the primary section of this diverter valve on ebay here is one item no 360066839150
As for energy efficiency advice above your boiler is not a permanent pilot model. The only problems it ever has are the ones you describe if you bought new valves as Tony advised you would probably get another 10 years after which we will all be burning logs as there won't be any gas.. Actually I expect to be burning logs quite soon at todays gas prices. And i am going to knit my own solar.
The cost and management accountant in me does not buy the replace a band d with band a boiler argument. Anyone who falls for it is ignorant of capital project decision analysis.
Domestic hot water section shown it that link won't help you, you only need to buy a replacement front section of the diverter valve these are quite easy to replace as i have said already.
Update
Alpha 240p is a permanent pilot model, i look after approx 40 of these boilers on a yearly contract .
Alpha 240p is a permanent pilot model, i look after approx 40 of these boilers on a yearly contract .
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