Ravenheat HE85T combi boiler issues

5 Oct 2004
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United Kingdom
I am one of the unfortunate owners of a dreadful Ravenheat HE85T combi boiler. Its nearly 3 years old and has had since it installation:
1. New CH sensor 2 years ago
2. New DHW sensor 2 years ago
3. New divertor valve 1.5 years ago. The system was flushed a few times and then filled with cleaner and then inhibitor. I also installed a Magnaclean and clean it regularly.
4. New fan PCB (small credit card sized PCB) 6 months ago.

The boiler at the moment runs fine most of the time but I've these 2 intermittent issues:
1. The boiler is in DHW only mode at the moment but sometimes CH starts on its own after a DHW tap is turned OFF. this happens about once or twice a week at the moment.
When this fault occurs, sometimes the ON/OFF switch on CLOCK behaves in reverse logic as well. When I turn the CH to ON, it turns CH OFF and vice versa. The issue is resolved when I reset the power to boiler.

2. Sometimes I get this old issue of intermittent DHW in the shower. It happens mainly when CH is off. Does it need new CH/ DHW sensors again?

Thanks for your replies in advance..
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it could all be one related problem.
if i were you, id junk it and start again. how much money have you spent in the last 3 years?
no matter how much you spend, it isnt going to be a new boiler. i think its dead money.

the problem is possibly a pcb.
Sorry chucking it and starting again is not an option at the moment. The memory of spending all the money including the cost and installation of a new boiler are still afresh:)

The boiler is working fine now 99% of times.

Could it be a clock issue rather than a PCB?
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I hope this thread passes attention of those who are specialists on Ravenheat (like Slugbaby)..

Yet to get any wiring checks from forum or anything to report back!
Hi All,

I have a Ravenheat CSI 85 and it knocks off after 20 seconds. I have changed both Temperature sensors, new fan and new Air pressure switch and still nothing happening. Botyh the Flue and venturi are clear too. Any suggestions would be invaluable. Thanks

Ray, you should not be accessing the combustion area of your boiler.

We don't give advice on those issues here.

The only advice is to get a gas reg engineer happy to work on that model ( many are not! )

1. When you say it goes into CH mode when a tap is closed.
Is the burner still firing?

2. 9 times out of 10 dirt in the plate heat exchanger.
Remove flush out and replace.

Sounds like the boiler was installed on a dirty system.
DC you are replying to three year old issues!

Hopefully by now that boiler has been replaced!
Hi Kia

I have had a gas engineer carrying out the replacements and he is now baffled too. I personally know nothing about boilers at all. Just looking for opinions. Thanks
Regardless of what you are doing we don't give advice to DIYers on gas/combustion matters!

If you really have an engineer the get him to ask in the engineer's part of this forum.

If it was an engineer doing the work then why did you say "I" in "I have changed both Temperature sensors, new fan and new Air pressure switch and still nothing happening. Botyh the Flue and venturi are clear too."


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