Alpha 240 eco water leak from flow valve

[aclarke]

I noticed a leak last weekend from the DHW flow valve that joins on to the diverter valve. This has not affected the DHW or the CH yet but I guess it won't be long before it does. I'm catching the drips in a bucket to keep the cellar floor dry!

Is this simply a matter of changing the diaphragm or is it a bigger job than that?

Thanks for your help.

 

[namsag]

IF it is leaking from where the pin comes out it only need a new gland nut take 5 mins

 

[aclarke]

Thanks namsag.

I've had a closer look and it looks like the leak is from the bit where the flow valve and diverter valve are secured together by the two crews. There are two empty screw slots and though I cannot be sure I can see water leaking from there.

 

[Agile]

Thats much more involved!

Most people would just replace the whole valve.

Its probably the rear seal in the diaphragm unit leaking.

For somebody with considerable skill it would be possible to replace just the leaking seal. We would never do that commercially though. The cost of the extra time would not be justified compared with the cost of the valve.

Tony

 

[aclarke]

Thanks Agile. I do have a spare valve I've taken from a second hand boiler in case that's needed. I've dismantled it all and I now know what it all looks like from the inside. I cannot use this seal as it looks old and worn, which is expected!

If I need to replace the seal only then do I order a service kit or can I get the seal itself from somewhere? It's my boiler so commercially I'd like to go for the cheaper option, if possible

 

[gas4you]

If its leaking from the rear of the diaphragm unit, its only a 30min job to take this off and usually just a minute 'o' ring thats needed.

Bet a Baxi service kit the 'o' ring is in this.

 

[aclarke]

I've checked it with a torch and it's definitely leaking from the rear of the diaphragm unit - from the screw holes.

If I only need the 'O' rings, where can I get them from? If it doesn't require ordering from the manufacturers then there's a local plumbers merchant I can go and see if he has any.

Would it be worth ordering the full diaphragm service kit and change the lot if I'm going to open it up anway?

 

[gas4you]

Yes, but you usually only get 1 minute 'O' ring in that.

Baxi are the same but 1/2 the price os Alpha parts.

 

[Gasguru]

You will find boiler O riings are non standard in size and most plumbers off the shelf sizes will not match. You must also consider the risk of a serious water leak if using non-genuine rings.

Take off the front section (just the 2 small pipes and "hex" screws. You can then determine whether the leak is fron the front section or the rear diverter section.

O ring and seal kits are available from Alpha but some of the Baxi kits will fit and are cheaper.

The Alpha refurb kit for the rear diverter section does not contain all the rings required. It is advisable to get the large rear O ring to seal the bypass section and the two smaller O rings for each end of the bypass pipe at the back. Don't forget a new auto air vent and drain-off as they are liable to leak afterwards.

 

[gas4you]

The 'O' ring i am talking about is about 2mm diameter

 

[aclarke]

Thanks guys.

Just went to the local plumbers shop and he has the service kit for £15. It contains the rubber diaphragm, nut, a small black 'o' ring and a larger silver one. However, it doesn't contain the lubricant.

I will collect the kit tomorrow or Monday as the one he showed me had the diaphragm slightly damaged with the nut having dug into it.

Thanks for everyone's help! I'll keep you posted.

 

[aclarke]

Sorry for the late update, didn't get to do anything on it until last week.

I did get a kit from the local plumbers shop and surprisingly it was much cheaper than what I was originally quoted - at £11, a bargain!

Anyway, I noticed the top nut that secures the diapgram unit and the diverter section was loose but decided to open the diaphragm unit anyway. There was a bit of gunge between the seals but other than that they looked to be in good condition so I gave everything a good clean. I didn't replace anything but while tightening the top nut again I realised I had to apply slight pressure to the diapgram unit to hold it in place as the two pipes connected to the unit looked to be making it slightly awkward to secure which is probably how the nut became loose in the first place.

The leak looks to be fixed - it's been several days now and so far so good. I'm keeping the service kit handy just in case

Thanks for everyone's help!

 

[gas4you]

You obviously got the Baxi diaphragm kit rather than the Alpha. Alpha include a very small tube of lubricant but charge twice the price of the Baxi equivalent

 

[Keith9534]

Sorry to dig up an old thread but...

Has anyone got an exploded diagram of this valve?

I have a service kit which has springs etc.

Is there a diagram anywhere on the net?