Worcester heatslave 15/19 issues

[oilhead]

The BHO 11 box became obsolete in the early 90's. Given the age of it, from experience I would think that this is the cause of your problems. I've never seen a B9 burner with such a box on it. Replace the box, base and photocell for a current Satronic set up, https://www.hwos.co.uk/tradestore/o...-boxes/satronic-tf830-conversion-kit-tf830kit.
This will give you all you need c/w a flange to modify the photocell hole.

 

[Cricket]

The BHO 11 box became obsolete in the early 90's. Given the age of it, from experience I would think that this is the cause of your problems. I've never seen a B9 burner with such a box on it. Replace the box, base and photocell for a current Satronic set up, https://www.hwos.co.uk/tradestore/o...-boxes/satronic-tf830-conversion-kit-tf830kit.
This will give you all you need c/w a flange to modify the photocell hole.

Thanks for that.

I'd already decided that it could only be a combination (of sorts) between the cell and control box, just really didn't know why or rather wanted confirmation.

I'd spoken to Danfoss myself today trying to track down the cell and they repeated what the merchant had told me about obsolete parts, which you already knew.

As they'd taken the time to give me updated part numbers and I'd found some in stock locally, I went with the Danfoss set up, everything required for £88 incso a result there.

Wiring was a but of a pain because of how it was wired previously but worked everything out eventually and fingers crossed they now have DHW & CH running.

There's some more wiring needs sorting out, such as the external programmer is not fed from the boiler but from a spur, the room stat seems to be wired into the frost stat block. Those are pretty straightforward hopefully.

Thank you for everyone's input

 

[oilhead]

These old BHO boxes were fed from the mains, with the thermostats (control and limit) wired through a loop. The current Danfoss box also needs a link across the preheater connections, a feature the Satronic does not have. As regards the programmer, you can still feed from the spur, just connect up the switched live. I suppose the original integrated programmer is long gone. I can't suggest how the room stat can be wired into the frost stat block without seeing how the boiler gets its power. Getting the job done soonest is the priorty and by the time you add VAT and c & p there's not much difference.

 

[Cricket]

These old BHO boxes were fed from the mains, with the thermostats (control and limit) wired through a loop. The current Danfoss box also needs a link across the preheater connections, a feature the Satronic does not have. As regards the programmer, you can still feed from the spur, just connect up the switched live. I suppose the original integrated programmer is long gone. I can't suggest how the room stat can be wired into the frost stat block without seeing how the boiler gets its power. Getting the job done soonest is the priorty and by the time you add VAT and c & p there's not much difference.

Yes the link was needed and other than working out how and why the motor feed looped through the control panel it went well enough.

That price (£88) was fully inclusive of everything, the total cost of parts required for a resolution. They dropped from over £100 because I spoke nicely to them

It looks like there was never an onboard programmer, just the 3 way switch. The owner confirmed the addition of the external programmer & room stat was carried out by an electrician at a later date.

WB says in the manual that the programmer should only be powered from the boiler not the other way round and there is a block for these connections, where the 3way switch was connected. I suppose they were worried about having a 2nd supply that could keep the burner running if the high limit stat said stop?

The room stat has just 2 wires that are fitted in the frost stat block of the control panel. I'd suspect this means the wall stat will override any control thats off, such as programmer or boiler stats?

The neutral of the main feed is also not in the main block but in an adjacent one, I'll move it but it's working anyway, just sloppy work.

 

[Cricket]

Just in case anyone in the future finds this thread and the enclosed sheets from danfoss do not make specific mention of it:

If there's no preheater fitted you need a link between terminals 3 & 8 otherwise it's an instant lockout from your new control box.