Boilermate 2000 not switching boiler on?

[Lozzmeister]

Hello, I'm new here, in desperation!
I have a Boilermate 2000 (which luckily has the Gledhill Switch for emergency hot water etc) and it seems that its not switching power through to the boiler.

It all started with the Fan in the boiler burning out last week (Ideal Slimline Classic) Had a chap in who replaced the fan and after some troubles with the PCB on the boiler he got it all up and working again.

This morning the boiler would not run at all.. I've had a good look at these forums and checked out quite a bit of the diagnostics as they've been described everywhere.

To summarise:- All pumps run as they should do and when the ACB on the BM indicates.
The thermostat input and output from the ACB also switches correctly, checked with a multimeter.
I followed the directions on the installation details and all the indications of the LCD's are as expected when running their diagnostics sequence.

Despite all this there is no voltage output to the Boiler of the switched output from the ACB.

Is there any other factor that I need to check before assuming that the ACB is faulty?



Just checked one more thing, and have coupled a live feed through to the boiler and that works fine as well....

 

[Slugbabydotcom]

Am I right in saying that LED 4 is not used on this model?

Had a similar problem with the heating output on one last week. The houseowners dad was there and he was a bit clever with a soldering iron.
It was discovered that there was a temperature sensitive fault on the octocoupler chip to the right of the relevant LED

He managed to re-route the supply to LED4 which was spare. All it took was one cut on the board to isolate the existing supply and one wire to jump the current to the previously redundant track. The heating pump or as it would be in your case the boiler switched live wire would need reconnecting to the appropriate terminal

Before you go hacking about just check the area for dry joints first.

If you cant sort that out then Gledhill will be the cheapest supplier at £171.19 inc vat and postage. Here's their number 01253 474 402

 

[Lozzmeister]

Many thanks for that info, I don't suppose you also know where I can get a pcb layout diagram?
It sounds like the guy got lucky with the soldering iron as I'd bet he had to guess where to make the track cut!
I connected a live feed to the boiler on a switch which is funtioning OK, as it cuts off via the boiler stat, but obviously I won't be leaving that in place or switched on while we're out of the house.
I'll be phoning Gledhill tomorrow and Wimpey as its their heap of a house that has gone wrong from the very start!

Thanks again.

 

[Slugbabydotcom]

Sorry I cant help with the circuit diagram. Maybe Gledhill can help? It wasn't too hard to trace the lines back from the output connections. I should have taken a pic of it!
The guy was going to swap the octocoupler over until I offhandedly suggested using the the full output line from where the signal to operate the pump came from.
He soon spotted the place I was referring to and did the rest. To help you figure out where this was I can say it was in the region of the Triac
It should be a doddle for a TV engineer if you have a TV repair shop nearby.
Heres a couple of pics after the modification with LED4 lit instead of LED3 and the output wire moved to terminal 16
Your problem I believe is from boiler LED1

 

[Lozzmeister]

Many thanks indeed. Given all the other factors in that the whole system works fine with a live feed to the boiler I can assume that this may well be the same fault.
Luckily I have access to a wiring shop (I'm a radar engineer) so I'll whip off the pcb and have a look at it closely.

Update: spoken to Gledhill who tell its common that if you get a spike on the line the triac that provides the output to the boiler sw. o/p get blown.
Its just as easy to swap the triac from the 4th led or fit a new one... which is relativley easy for me to do.