No Heating. Hot Water OK. All 3 Status LED's Lit all the time and DHW Pump Runs Constantly

Hi Guys

Hot water is fine but I cant get Heating to Work.

Stating to notice a problem when the boiler was trying to continuously fire when we had turned room thermostat up to switch heating on. We then noticed radiators were not heating up. I did manage to fool the system by turning the main boiler off then turn Room Stat on, after about 5 minutes radiators would heat up, then I could turn boiler back on but after 5 minutes boiler would go back into a loop of trying to constantly fire.

I took panel off Boilermate 2000 and found a user manual stuck inside and tried making sense of it. I have found all 3 Green Status LED's are constantly lit even with not hot water flowing or heating demand. They are on all the time and I noticed the pump on the right which I think is the DHW pump is constantly running.

I have tried to get fault codes by presing SW1 for long and short presses but I get no read out. Also tried SW2 but no fault codes come up the display does not change.

I personally think its the the main PCB (ACB Appliance Control Board) but I would like an experts opinion.



Edited... Just to add: I have just read more info in the Manual and can confirm no other Horizontal Red LED's on the top display switch on when Hot Water is Turned on or if the Room Stat is Turned fully up.

No need to respond now. I did some additional testing myself and decided to purchase a GT155 PCB for £180. Fitted it, performed a successful self test with Jumper 5, then removed jumper 5 and tested heating, hot water and all performs really well. All LED's work as designed to do unlike before.

Also just to add the self diagnosis SW1 and 2 also work now. To test just hit SW2 and keep clicking through to see readings. I didn't try SW1 but looking at Instructions it takes you to sub menus. All I know is I've saved a fortune. The plumber who came out the day before was not 100% sure of his diagnosis because he was not familiar with my set-up so he did not charge me a call out fee. He was quoted £265.00 + VAT for the PCB then he would have charged Labour for fitting it!


So thanks to myself and you never know this may help somebody else. ;-)

Where did you source yr board from please snd how much was it. Was it hard to fit?

Thanx

Lenny