Main 24HE combi boiler - leak / part identification

26 Apr 2023
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United Kingdom
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Hi all,

I'm getting a persistent leak from my combi boiler unit. It fills a 500ml container a week, so it's not 'critical' just yet.

I do not intend to fix this myself. I want to save time and identify what parts I might usefully get for whoever comes and does this repair for me.

Here are a few pictures. There is a video, but I'll hold off on sending that for now.

My ask - can anyone help me identify the parts I should buy, even if they might need to be returned. I'm just keen to save a bit of time on the repair.

My photos:


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The leak is on the 3 way valve assembly, might need a new one, or might just be ok to clean up. @gas112 or @ianmcd might be able to confirm this for me.

Correction to warning - there is no "gas work" involved in this, and we are advised no part of access involves breaking an air seal unlike many later boilers,
Some parts identification is here (not all that are leaking)
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Thanks Chris (for the 11th time today...). I'll wait to hear from the other crew, but it sounds like my shopping list so far includes a full stack of o-rings/diaphragms. I assume for both the DHW Pressure Differential Valve (front bit) and the Diverter Mainfold (bit at the back), which has most of the evidence of leakage. I guess there's a time/cost to clean vs what might be a shorter time to replace, so an interesting question on best use of time/money. Not wanting parts to go to scrap, I'm inclined to repair if it can get me to a non-leaking/safe boiler again.
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Reactions: CBW
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Looks like it can be repaired as peen @gas112, so if everything is in that kit, just order one, or tell your engineer to. Cleaning that wouldn’t take long, so get it cleaned off.

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