Worcester Heatslave 26/32 CH operation problems

[CharlesY]

I would also check there is a hot water off wired into the timer and if there is one, make sure it hasn’t come loose/detached

No, there is not. Definitely NOT.

 

[CBW]

OK, NO NEED TO SHOUT. Also I didn’t say your valve WAS that one.

 

[Hairymelon]

It’s possibly one of the earliest heatslaves that did have the valve the other way round. What is the exact model please

 

[CharlesY]

Charles, I have read it several times, including the additional posts, and you keep saying at rest it’s at position A for hot water and mention position B for central heating. Please see image of Danfoss, but there’s generally an industry standard:

View attachment 290221

I can't see a way to take your valve pic out, so my apologies for repeating it.

Here's a pic of my Drayton, right side of controller body, indicator peg again clearly at rest at Position A, which is (in my boiler at least) the default resting position which is for DHW.
Position B is for CH.

CharlesY.

 

[CharlesY]

It’s possibly one of the earliest heatslaves that did have the valve the other way round. What is the exact model please

The valve is the usual "right way round".
The manual tells us the make and model is

Worcester Bosch Group GREENSTAR HEATSLAVE EXTERNAL 25/32
Floor standing external oil fired condensing combination boiler using balanced flue system.

It was installed in October 2013, and has run faultlessly till about 6 weeks ago.

CharlesY

 

[Hairymelon]

Has the new diverter been fitted correctly. I e port A. Upward and port B downward towards hot water heat bank (meaning brass body)

 

[CharlesY]

Has the new diverter been fitted correctly. I e port A. Upward and port B downward towards hot water heat bank (meaning brass body)

You are not giving me and Steve much credit yet!
Here is a picture of the Diverter valve we took out.
Let me know if you would like to see a photo of it dismantled.
I cleaned it up, refurbished as required, and reassembled it using the correct lube.

Now it is a 'good as new spare'.

But, in the boiler tonight, right now, is a brand new OEM Diverter Valve and controller complete.

CharlesY


PS - are you getting to see my photos OK?

 

[Hairymelon]

Thanks. Pictures don’t show A or B on brass body

 

[CharlesY]

You are not giving me and Steve much credit yet!
Here is a picture of the Diverter valve we took out.
Let me know if you would like to see a photo of it dismantled.
I cleaned it up, refurbished as required, and reassembled it using the correct lube.

Now it is a 'good as new spare'.

But, in the boiler tonight, right now, is a brand new OEM Diverter Valve and controller complete.

CharlesY

Thanks. Pictures don’t show A or B on brass body

Position markers A and B are shown only on the Drayton DV controller unit.
Note that the "brass body" has a right way up, and a wrong one. It is the right way up in the photo.

In the photo of the DV 'brass body' in position (with the controller off for clarity), there are three connections :

1. At the REAR horizontal, is the HEATED indirect water coming (about 4" ) from the circulation pump.

2. At the TOP is the delivery pipe sending heated indirect water to the CH system.
This pipe is labelled CH (by Worcester) which is a good clue.

3. At the BOTTOM is the connection to the main heat exchanger that sends heated indirect water to DWH system.

In Position A-DHW the internal flap swings UP under spring pressure which closes the outlet to the CH system outlet. The indirect heated water is diverted DOWN to the DHW heat exchanger outlet.

In position B-CH, the DV controller motor drives the internal flap DOWN and closes the outlet to the DHW heat exchanger. The indirect heated water is diverted UP to the CH outlet.

The DV valve is a simple 'double sided flap valve' that CLOSES to 'one or the other' outlet. It can NOT close both at the same time. One valve (at least) will always be open. The idea is that the DV valve can NOT block the flow (unless the whole system is choked solid, in which case it's time for new boiler anyway).

It is a feature of these flap-valves that as long as they close over fairly well, the modest water pressure inside the valve cavity helps to press the flap onto the steel ring seat of the outlet being closed-off. When the pump is running, these valves might need a bit of a nudge to lift them off their seat, after which pressure quickly equalises on both sides of the flap and then they become more or less free to move.

I noticed that according to the Manual, the circulation pump should always be set to III / 3 Maximum so as to cut down any tendency for deposits to lodge in the fine spaces of the heat exchangers. This also helps keep the DV closed firmly to one side or the other. Two good reasons to do what the book says.

Some clever people thought all this out. One has to admire them for it.

If I was as clever I would be able to work out what's wrong with my ^&*^%ing boiler!

CharlesY

 

[CBW]

So after some research, and thinking it appears your system is a W-plan. It would seem likely that a control is stopping the heating working after the hot water has been ran. I have also researched and could be pump overrun stopping it firing up.

 

[ianmcd]

DRAYTON "Hansen Class 'F'" DIVERTER VALVE

The Hansonclass refers to the synchron motor , not tha actual valve , the valve model will be on the plastic cover you have removed to take that pic

 

[oilhead]

Believe me, I've seen several Worcester programmers that work perfectly when doing normal tests, but in normal use refuse to change just like yours. One relay wil work, so will the other but some glitch in the circuitry will hold the open one on when you need to change. Turning off removes the stray current but the fault is still there next time.
Then again, you know your programmer is not faulty.
Also, when replacing the DV head, did you use the Worcester part or try to adapt the Drayton MA actuator? They are different.