Ideal C80FF problem: heating always on

[tadas]

Hello all,

Boiler is in "hot water only" mode but still heats radiators. I don't think it's the mode switch since it wasn't in use at all during the time it started. And it also "ignores" the heating setting and seems to go full on.

I found couple other threads mentioning similar problem:
https://www.diynot.com/diy/threads/ideal-c80ff-combi-problem.59793/
https://www.diynot.com/diy/threads/...or-something-i-can-remove-to-prevent-c.94461/
http://www.ukplumbersforums.co.uk/central-heating-forum/13722-ideal-c80ff-95ff-constantly.html

I found that DHW flow switch mentioned in both threads. It had some condensation, couldn't see inside. Carefully removed the cover. Nipple goes out/in pressing/releasing the switch when I open/close hot water tap. I also used multimeter in continuity mode to check the switch, seems to work OK.

Any other ideas what I could check?

I almost thought to get another main circuit board from ebay (since it's not too expensive) but I feel like it'd be unsafe thing to mess with (since it has pots for "min" and "max" "burner pressure" and I don't think I can adjust without manometer (?)).

Many Thanks

edit: I might be on to something!! Boiler did recover couple times after the problem started 2 days ago. While looking for a fault I left the switch lid removed, it had a chance to dry out and boiler is working again. It could be condensate/humidity inside the switch! Kind of makes sense.

 

[Agile]

The pin gland is leaking into the switch box.

You need to replace the gland and dry out the switch.

Tony

 

[easyflow]

The pin gland is leaking into the switch box.

You need to replace the gland and dry out the switch.

Tony

Would agree, Also this boiler in particular was a budget boiler when first introduced,
When you open it up it has nice quality brass and honeywell components, not like the tupperware boilers they manufacture these days.
I look after two of these boilers that are going into their 15th year with just a few minor breakdowns.

 

[Agile]

They do have good components but the combustion cover is a bit of a bodge.