Ravenheat Combi Boiler problem (Fixed thanks)

[Jaa]

My Ravenheat RSF84E(T) combi fitted new 3 years ago by myself but serviced by corgi engineer is giving intermittent problems on the domestic hot water side.
Turn on hot tap and the boiler kicks in as normal after 10 to 15 seconds it switches off again, if I leave the tap running it some times comes back on and works normally
but wastes a lot of water waiting.
If I turn the water tap off and on again it may do the same again or work normally.
On the last service the engineer could find nothing wrong with the boiler.
The boiler is not over used only used for washing and central heating no bath elec shower.
Greatful for any help. jaa

 

[Agile]

Is this a new fault following the last visit to service the boiler?

Could be a faulty DHW demand switch??? Or a temperature sensor?

Why dont you call the CORGi engineer to diagnose the problem?

Tony

 

[weareleeds]

Most of the time the fault you describe is due to a small amount of dust partially blocking pilot injector so change that if fault persists then suspect ign box on gas valve (especially the red one).ps i work on these crap things a lot as their uk base is in morley where i do a lot of work

 

[Jaa]

Is this a new fault following the last visit to service the boiler?

Could be a faulty DHW demand switch??? Or a temperature sensor?

Why dont you call the CORGi engineer to diagnose the problem?

Tony

Tony. I mentioned this fault to engineer at last service but the fault was intermittent and he could find no problem at the time.

 

[Jaa]

Most of the time the fault you describe is due to a small amount of dust partially blocking pilot injector so change that if fault persists then suspect ign box on gas valve (especially the red one).ps i work on these rubbish things a lot as their uk base is in morley where i do a lot of work

Hi, thanks for that, I live south leeds 3 miles from morley.lol.
Are you saying the boilers are rubbish or the ign boxes?
Would I be able to blow the dust away from the pilot jet or is it a sealed unit? cheers.

 

[gas4you]

probably means the boiler

 

[Rob]

Id changed the thermistors. These can be intermittant and produce the fault you describe plus is say its the most commonly changed part on ravenheats!

 

[Vinno]

Its the plate heat exchanger, its blocked! Take it out and clean it or flush the boiler and hope that that clears it.

 

[Rob]

Its the plate heat exchanger, its blocked! Take it out and clean it or flush the boiler and hope that that clears it.

I disagree. Blocked plate usually gives constant on-off. OP seems to be saying that it just fails to come back on at all!

 

[Jaa]

Its the plate heat exchanger, its blocked! Take it out and clean it or flush the boiler and hope that that clears it.

I disagree. Blocked plate usually gives constant on-off. OP seems to be saying that it just fails to come back on at all!

Ok i have just turned on the hot tap, the burner fired up, after 15 second it clicked off again, I left tap running for 2 min and it failed to re-light, turned tap off and on again same thing happened, waited 5 min tried a 3rd time and it worked nornally. !!

 

[Rob]

Next time it doesnt fire up or after its cut out, try wiggling the wires on the thermistor, worked for me last time!

 

[Jaa]

Next time it doesnt fire up or after its cut out, try wiggling the wires on the thermistor, worked for me last time!

? Rob do you mean the DHW thermostat?

 

[Agiile]

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Foolish post (by person using a fake name pretending to be another member) removed

Mod Rupert
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[pannierstan]

Jaa, next time it goes off, look throught the sight glass window and see if you can see the pilot lit or if its all out and nothing lit.

Stan

 

[Jaa]

Jaa, next time it goes off, look throught the sight glass window and see if you can see the pilot lit or if its all out and nothing lit.

Stan

Cheers Stan will have a look.