Problem with British Gas Boiler RD1

[ollski]

flow / return thermisters 12Kohms @ 21deg to 1.3Kohms @ 83deg.
flue sensor 125Kohms @ 21deg to 550ohms @ 200deg.

As bdl says though all comes as one with the harness.

 

[beermatt3]

Thanks for all your help, sorry I was a bit of last night, as you say one of those days.

I have put harness on order, should be with me tomorrow. Fingers crossed.

Thanks again

 

[Trance Nation]

The boiler is basically a classic chassis and heat exchanger, the pcb is not a 25 board. It was designed to allow British Gas to attach a modem and carry out remote diagnostics via their call centre.

Really !! ?? Thats a bit "Big Brother-ish" is it not ? Next thing u know theyll be monitoring the flue gases from a call centre and only doing a service when the boiler needs it ! lol !

Anyways joking aside, I wonder why that idea never went ahead ?

 

[ollski]

The facility is still being built into the new boilers (rd = remote diagnostics) and will happen at some point. I think the rac are using the same thing. I remember seeing on the news that they can phone you in the car just before it breaks down and guide you to the closest patrol van who will be waiting to fix it.

 

[J..M]

I think you need a competent boiler engineer who does not just change parts until it works.

Does such a beast exsist ?

 

[argon]

I have the same problem you had with your boiler. Did the part thermister harness solve your problem?

 

[mickyg]

squeeze the red thermistor with a pair of pliers til you hear it crunch a little.

 

[gavinda]

yeah the theimistor harness is usually the fault even when pcb is indicated to be faulty. its the only part ive evre replaced on these boilers.

 

[argon]

thanks for the info , its seems to have done the trick.... and have orded
a new part........

 

[nathan2003]

I am having the same problem. Please let me know if there is any luck.

 

[Buggaraboiler]

I had the same experience as beermatt3 called to a bg370 rd1 boiler was not starting up. I did the normal checks and and started reading through the manual as you doo!fault diagnostics suggests replacing pcb but at the bottom of the page (small chart about led's3&4) was telling you that if led 3 flashes (on pcb bottom right) for 1 sec it is a lockout and/or sensor fault
I measured the resistance of the harness across plug terminals and got red 15.7komhs blue 14.7kohms white 144.5kohms seemed ok i thought but replaced the harness any way as the boiler was locked out due to these sensors. And she fired up first time !!!!! Measured resistance again once harness was removed again same readings the readings on the new harness were approxamatley the same. Now I was confused. When I got home this had started to bug me a little so I checked again and this time got the same readings on the blue and white sensors but nothing on the red, strange any ideas??

 

[Andygasman2010]

Just realise how old this thread is... Probs better to start another one.

I know what you mean, I've come accross this a few times. I've come to realise that taking readings on these is pointless because they can be intermittant.

If I have one that shows sensor faults I just change the harness.

 

[flutterbye]

squeeze the red thermistor with a pair of pliers til you hear it crunch a little.

I've got the same issue and whilst waiting for the new thermistor harness to arrive, I thought I'd have nothing to lose trying the above and was pretty shocked to see it seemed to work!
No doubt this is a short term fix and I should replace with a new harness anyway? I've also no idea why this works nor how dangerous it is but several test cycles show the boiler going on and off as usual. In any case, I've got a new harness on order.

 

[Abcplumb]

squeeze the red thermistor with a pair of pliers til you hear it crunch a little.

I've got the same issue and whilst waiting for the new thermistor harness to arrive, I thought I'd have nothing to lose trying the above and was pretty shocked to see it seemed to work!
No doubt this is a short term fix and I should replace with a new harness anyway? I've also no idea why this works nor how dangerous it is but several test cycles show the boiler going on and off as usual. In any case, I've got a new harness on order.

Thanks guys this really helped out today.
After an hour trying to figure out this intermittent fault, I tried a quick search online which helped me out big time. A Good Friday wasn't going so good until I crunched the sensor.
Just want to add this works!! Had to do
Something as everything will be closed until Tuesday morning due to the long Easter holidays. The reading from the sensors didn't help much, it was worth giving this a shot.

 

[St0rmer66]

Interested to know why it works too... Sick of replacing these harnesses. It gets to once a year on some boilers! No leaks in the thermostat pockets or anything like that, they just die over and over..