Worcester Heatslave - heating issue

[rubber_hammer]

Hello... I'd be grateful for opinions on what may be causing the following symptoms on my Heatslave combi boiler (oil). When I turn the heating on, hot water will initially circulate around the system normally, but will eventually stop circulating and the radiators will cool down - but it does appear that the CH pump is still running and is quite hot. If I open a hot tap, I can hear a relay click and the boiler will give hot water to the tap AND it will also start circulating hot water around the radiators. I'd be grateful for your advice. Many thanks!

 

[Exedon]

Check 3 port valve working correctly.

 

[oilhead]

Check 3 port valve working correctly.

What he says

 

[rubber_hammer]

Thanks for your replies guys. Just a bit of a follow-up. I forgot that I had previously put the diverter valve manual switch across (which I presume gives both hot water and heating?). I think the heating stopped last winter so I did that to get it going again - boiler was hardly used since spring then. So, I should probably start again with my request for help...

After a bit more looking today - it appears that the rads will only heat up when the diverter manual switch is pulled across. So, I'm guessing there's a valve or motor issue there.

However, the pump on the boiler will not come on when the heating is turned on. It only comes on when the hot water is on/active and the burner comes on to heat the water - which is either when it needs to get up to temperature or when the hot water tap is opened. Once the burner stops, the pump stops (I'm gauging this by feeling the pump vibrations, and also feeling the hot water entering the rads). I don't even know if the pump should be running with the hot water - but it doesn't make sense that it should run constantly when the burner is, but no hot water taps open (just guessing here).

Is there something obvious wrong in that the water pump is not being called in when the heating is on? The pump is not activated when the hot water is off and the burner is running with heating on.

Hope the above makes some sort of sense.

Thank you!

P.S. seems similar to this post: https://www.diynot.com/diy/threads/worcester-15-19-ch-comes-on-when-only-dhw-should-be-on.127605/

 

[Exedon]

You already know 3 port actuator is not working correctly replace .

 

[Harry Bloomfield]

After a bit more looking today - it appears that the rads will only heat up when the diverter manual switch is pulled across. So, I'm guessing there's a valve or motor issue there.

The 3 port faulty!

 

[Burnerman]

I put a new power head on mine......the Honeywell seems to be best but I have used the Toostation
equivalent.
John

 

[Exedon]

Maybe post picture of said 3 port some use a Drayton valve others Honeywell with a grey plastic head.

 

[rubber_hammer]

Thanks everyone. I'm assuming the actuator calls the pump in then?

It's a Honeywell V4044F1109 with 5 wires.

Is your recommendation only to change the actuator, and not the actual valve? The valve seems to be switching ok with the synchron manual switch (if that helps any).

Thanks again!

 

[Harry Bloomfield]

The head/the actuator/the top section is the common point of failure, they wear out - microswitches fail, the motor fails, the mechanism wears out. The actual water valve below it, tend to be much more robust, as well as more difficult to swap - so the usual advice is to just change the actuator.

They are such a common point of failure, and so cheap, so easily swapped - it's well worth it to keep a spare one to hand, ready to fit.

 

[Exedon]

As above just change head but when it's off just check the valve itself moves smoothly.
On that boiler the 3 port itself can be an absolute pig to change!

 

[rubber_hammer]

Thanks guys - much appreciated. With regards to the head, do I need to match up the exact model, or can I fit other model numbers that have the the correct mountings and have 5 wires? There appears to be a big difference in pricing between this exact model and others that appear to be similar. I appreciate some wire joining may be necessary, so some don't come with a connector plug. I appreciate that some of these other models may have different micro switches etc too. I'd rather not learn the hard way - but I'll gladly save a few quid if I can.

 

[Harry Bloomfield]

Thanks guys - much appreciated. With regards to the head, do I need to match up the exact model, or can I fit other model numbers that have the the correct mountings and have 5 wires? There appears to be a big difference in pricing between this exact model and others that appear to be similar. I appreciate some wire joining may be necessary, so some don't come with a connector plug. I appreciate that some of these other models may have different micro switches etc too. I'd rather not learn the hard way - but I'll gladly save a few quid if I can.

Fit the same model head, then it is certain to work.

 

[rubber_hammer]

Fit the same model head, then it is certain to work.

Fair point. Thank you!

 

[Agile]

The head contains a microswitch which brings on the boiler with pump when the valve is moved to a position.

But it is most likely to be only a failed motor. Just changing that is likely to be the easiest and cheapest option. Often called Synchron motor as that is the brand name of a well known manufacturer.

Often available for around £10.