Ferroli Optima 701 - Long delay before fire up

[woodenbloke]

I am experiencing a long delay of one to five minuites before the boiler fires up.

The fan runs so I know the flow switch works.
I have had a multimeter across the air pressure switch which is fine.
The LED row indicates all ok.

The DHW thermistor reads a correct resistance for the expected temperature and seems to vary correctly.

So I am left thinking main PCB?

When it eventually does fire the DHW is incredibly hot, but as the thermistor seems to read correctly, this also points me to the PCB.

Any thoughts or similar experiences would be greatfully recieved.

Tim

 

[DeltaT]

A great wee boiler, no divertor valve, two HXs & limited componants.

Does it do the same thing on HW & CH??

Sounds a bit like a faulty Modureg. It's funny, we had a whole estate with these combis & the PCBs would look completely f.cked, but it was rarely the problem.

Of course you do know there is a 3 minute delay before it'll fire up after shutting down??

Are you a GSR RGI by the way??

 

[woodenbloke]

Thanks Delta,

Yes, it does seem to do the same on both HW and CH. Intermittantly though. Sometimes fires striaight up, other times long delay.

Yes, I was aware of the 3 mins delay, but the problem can also occur from cold.

I like the idea of the Modureg but the relay on the PCB isn't even switching. Nor is LED 7 (indicating air pressure switch) lighting despite the pressure switch checking out with a meter. Then eventually LED 7 lights, the relay switches and the boiler lights.

No, i'm not a GSR RGI. Just an end user getting annoyed with waiting for a hot shower!

 

[DeltaT]

Hmmmmmmmmmmmm........Not a RGI eh, well anything Gas or in the combustion chamber, sorry I can't advise. You'd need to go into the 'combustion chamber pot' section of the forum for that!!

Well, LED 7 is fan/APS so venturi may need cleaned & that's combustion chamber mate, sorry, but you need a RGI.

PLEASE DON'T TAKE ANY CHANCES BY DOING ANYTHING FURTHER YOURSELF.

 

[kevplumb]

go on tell him how puller

exept you dont know

stick to driving your desk SFB

 

[DeltaT]

No, no Kev(my official stalker) the OP is not competent enough to work on his gas appliance son. I was excluded from the combustion chamber pot, but that's of little interest to me now, as I know it is full of CC/CCCs & CPSs.

 

[kevplumb]

oh the usual carp

you where voted out of the CC
for being a pratt

 

[DeltaT]

The OP gave me a bit of a bum stear when he stated all the LEDs were OK!!

 

[gas_man_gaz]

mod7 why have ya left delta's post suggesting a faulty m-reg? and removed mine stating whats most likely to be at fault (venturi)
in the post i didn't advise the op that he should attempt a repair or even how to do it