British gas 532i boiler

[Loki]

Have a problem with a boiler it is a bg 532i combi which I believe is a slightly modded Worcester bosch greenstar.
problem is with the heating side of the boiler it does not work. Unless you use the ch boost (chimney sweep) button. I have linking out the room stat and still no joy. Question is does the boost button go thought the same sequence of events and controls as a demand from the stat. Therefore does this verify that the diverter valve and the micro switch thermistor etc are all ok or does it bypass some?.


Many thanks

 

[bigads28]

If you use the chimney sweep button it moves the diverter into ch position and then runs in the normal manor depending on where you have the ch control set min or max.

What kind of controls do you have? Make sure you have power at the s/l.

 

[Loki]

Power is coming to the switch from the wireless receiver (British gas wireless which I believe is just Drayton)when demand is on.
I have not had much experience of fault finding on more modern electronic boilers but I understand most people change the pcb when it is not necessary but not 100% if the pcb is a problem.

 

[bewsh]

I'm sure in chimney sweep mode, it ignores one of the temperature sensors, I think the one by the heat exchanger, with an orange clip? Check the resistance of that.

 

[Loki]

I was getting 9000 ish ohms at room temp 15 degrees not exact sorry lost temp sensor for my multimeter. But not sure if it is knacked because I cannot find what the reading should be for this Ntc?

 

[solutions]

I was getting 9000 ish ohms at room temp 15 degrees not exact sorry lost temp sensor for my multimeter. But not sure if it is knacked because I cannot find what the reading should be for this Ntc?

This may help you if you can pin the temp that your reading the resistance at down.

 

[Clint 1979]

Hi Loki,
If you need any doner parts I'm taking an RD532i out this Thursday (combi swap), and it works fine.
If you're anywhere near South London it's yours if you need it (or the pikeys will have it)! :tounge_smile:

 

[bewsh]

9kohms at 15 isnt right then. It could be a faulty stat then. Worth a go before spending lots on a pcb

 

[Aquazone]

I have had this numerous times and always been the low ratio out.

In chimney sweep mode boiler runs at max, but if not in service mode and CH dial is on 2/3 runs on low, and can either baffle out or not ignite.
Also if you put into chimney sweep mode then turn dial to 1 might get it to fault.
Otherwise call Worcester as they may have an idea before PCB

 

[solutions]

If you follow this link to the ukpf pdf and document store you can click on Croppie' s generous link to his drop box where you will find amongst many other usefull documents worcester bosch' s pdf containing the above previously posted thermister resistances and the details on setting up the gas valve high and low fire gas rates.
http://www.ukplumbersforums.co.uk/showthread.php?t=70751
P.d.f & document store

Thanks again Croppie for sharing your valuble resource. If anyone follows the link or makes use of Croppies drop box material please make a point of thanking his post containing his drop box link on the ukpf pdf and doc thread.

 

[bewsh]

I have had this numerous times and always been the low ratio out.

In chimney sweep mode boiler runs at max, but if not in service mode and CH dial is on 2/3 runs on low, and can either baffle out or not ignite.
Also if you put into chimney sweep mode then turn dial to 1 might get it to fault.
Otherwise call Worcester as they may have an idea before PCB

Wouldn't that cause it to lockout though?

 

[bewsh]

Actually, he hasn't mentioned if it locks out on c/h.

Does it lock out or just not run at all?

 

[Loki]

First of all Clint thanks for the offer of the boiler but I'm in north suffolk so not worth the trip to Croydon. Also to solutions for the resistance chart.
The boiler does not lock out just does not run. Pump runs but does not seem to start ignition sequence.

 

[bewsh]

If it doesn't lock out, I wouldn't say it's down the CO2 %.
Definitely worth checking the temperature sensor resistances against the chart.