Heatslave 20/25 no power to room stat

[Incrisis]

Hi everyone

I hope this isn't too long winded, but I understand how it is best to have all the info before trying to help. My boiler is working fine for water, but not for heating.

Heatslave 20/25 boiler, approximately 19 years old.
When fitted, no room stat fitted.
A few years ago I posted on here, got some great advice, and fitted a room stat, Beok BOT W313.
Has been working fine until today.
Had a 24 hour power outage, thanks storm Eunice, and when the power came back on, the room stat won't switch on.
I initially thought that maybe when the power came back on, the surge killed the stat, it is only a cheap thing and I know that sometimes, around here, when power is restored it can go on/off a couple of times before settling which may have fried the stat controller.
I removed the wiring for the room stat from the boiler wiring panel and reinstated the link that was there before fitting the stat.
However, even though the rads are cold, the heating doesn't kick in. The control panel on the boiler has the heating set to permanently on.
When I turn the hot tap on, the boiler kicks in.
I am guessing there is no power getting to heating side of the control and therefore no power getting to the room stat.

The one saving grace I have at the moment, apart from a couple of electric heaters, is that the diverter valve in the boiler is sticking (again, can't remember how many times I have changed it over the years), so when the boiler needs to reheat the internal hot water tank, or I run the hot tap, it pumps hot water around the rads as well, so I am getting some intermittent heating.

 

[CBW]

If you put the link in, and it fails to operate, and you mention the diverter sticking, then it could be this?

 

[Incrisis]

If you put the link in, and it fails to operate, and you mention the diverter sticking, then it could be this?

Hi Chris

As far as I know, on this boiler the diverter valve simply opens/closes the hot water feed to the rads when the heating is on/off. It can be a bit annoying in the summer because when you turn the hot tap on, it also sends the hot water around the rads, so when it is sticking, like now, in the summer I end up having to turn all the rads off until I replace the valve.

What is happening now, is that it seems there is nothing telling the boiler it needs to kick in the hot water supply to the rads, but does kick in when running the hot tap, or the internal hot water tank needs reheating.

 

[CBW]

In which case then, I’m wondering if the surge has damaged the pcb, seems odd though how hot water is working. Might be one for the oily’s.

 

[oilhead]

If you are using the integral programmer, this may be the problem. They are easily damaged by surges. Follow the circuits with a multimeter to prove supply.

 

[Terrywookfit]

link brown and grey wire.
does relay click.

 

[Incrisis]

If you are using the integral programmer, this may be the problem. They are easily damaged by surges. Follow the circuits with a multimeter to prove supply.

I have found my multimeter, tried looking for it last night and couldn't find it anywhere... but anyway, any circuits in paticular?
I have the dual programmer fitted, one for water and one for heating. The display looks fine, I can scroll through the heating off, once, twice, on and the boiler is kicking in when I turn the hot tap on.

link brown and grey wire.
does relay click.

Where are these located?

I used the multimeter on the output live/neg for the room stat and it showing zero, so I am assuming something is stopping the power getting to the block.

ETA: I checked the fuse on the circuit panel and it is fine.

 

[Terrywookfit]

On the Programmer if internal or selector switch

 

[Incrisis]

It has the dual programmer, like the one in the picture.

Obviously wasn't using it when I fitted the room stat, and I removed the wiring for the room stat yesterday because the digital screen was blank and wouldn't switch on, reinstating the link on the PCB. It looks like there is no power getting to the block on the PCB that you wire the room stat into.

 

[Incrisis]

Coming out of the programmer, there are 5 wires, Grey, White, Orange, Brown and Blue.
The Orange and Brown are wired into the same hole of the 'chocolate' box connected to the PCB.
So I need to link the Grey with the Brown on the chocolate box to check the relay?

Sorry for dumb questions, I am kind of ok with doing must stuff, but would prefer to not mess the boiler up more than it already is.

 

[ianmcd]

yes link the grey and brown, the relay in the timer may have fused

 

[oilhead]

Check on the PCB terminal block for power to the CH and HW connections. If the programmer is switched on you should have 240 volts if you haven't then programmer is kaput.

 

[Incrisis]

Thanks for the replies.. I haven't had chance to link the grey and brown wires, will hopefully give that a go tomorrow or the next day... working 12 hour shifts limits how much spare time I have.

 

[Incrisis]

Check on the PCB terminal block for power to the CH and HW connections. If the programmer is switched on you should have 240 volts if you haven't then programmer is kaput.

I checked where the room stat connects to the PCB and I am getting nothing.
I checked between 2&6 and 3&6.

 

[oilhead]

You need to check where the outputs from the programmer are connected to the PCB. If you have no power there, you will have nothing to the room stat.