Boiler not firing for heating ok for water

[Helptav]

Hello all. As per title. Traditional set up tanks in the roof hot water cylinder 18kw boiler with filter. Has happened before but mostly comes on instantly. Yesterday for first time our heating didn't want to come on for ages. Only thing I think if is to change the head of the 3 way diverted valve thoughts please? Came on in the end and seems ok (for now) thanks Paul

 

[Helptav]

Hello all. Tried this morning water comes on perfect when using programmer how ever heating does come on but takes a good 5 mins to fire up boiler thoughts? thanks

 

[terryplumb]

3 port valve issue most likely. Can you use a multimeter to check wiring at the wiring centre ?

 

[Helptav]

Thanks terry i dont own a multimeter, however if i replace the full head do you think this will solve me problem ? Thanks for your help Paul

 

[terryplumb]

It would if the problem is definitely the valve. Checking voltages at the wiring centre would confirm this.

 

[Helptav]

Thanks Terry,

 

[ianmcd]

what time clock and room thermostat do you have ?

 

[Helptav]

Hello Ian both Drayton, the programmer is like the following https://www.toolstation.com/drayton...VDe3tCh2aLQmHEAQYBiABEgIr8fD_BwE&gclsrc=aw.ds

 

[Helptav]

Room Stat like the following, im guessing i have a drayton 3 way valve, has a plastic top looks like the following
https://www.screwfix.com/p/drayton-...VjqztCh2s3QJ5EAQYASABEgIzbvD_BwE&gclsrc=aw.ds

https://www.screwfix.com/p/drayton-ma1-679-3-3-port-motorised-valve-22mm-22mm-compression/81844

 

[ianmcd]

Thanks the programmer and room stat are pretty reliable, have seen faulty of both but they are pretty good, the zone valve actuator however are bad , as said if you could check the voltages would be best, but my money is on the actuator

 

[Helptav]

Thanks, if you was me would you replace the top of this? have i understood correctly? or does the system need draining down to fit new one complete? Thanks Paul https://www.screwfix.com/p/drayton-...VzO3tCh3-sQJ_EAQYAyABEgLcGPD_BwE&gclsrc=aw.ds

 

[ianmcd]

no need to drain anything it just pops off, you might want to get one of these too, trust me makes life so much easier, going into wiring centres can be a complete nightmare , for all they cost, and if you ever need to swap it out again in the future takes 20 mins

https://www.ebay.co.uk/itm/303590875540?epid=1405254704&hash=item46af6d2194:g:fr8AAOSwhZhd58xk

Available in lots of merchants just used the ebay post to show you what I mean

 

[Harry Bloomfield]

If the 3-port actuator is sticking, then I find you can sometimes get them to work by giving them a thump, but only until they stick again. If you look at the 3-port and out the make and model - often you can just buy the head/actuator part, which makes it a fairly easy swap - Just a couple of screws and maybe four electrical connections.

If considering swapping just the head, it's worth checking the valve spindle is free to turn and free from leaks.

 

[Helptav]

Thanks Both

 

[Helptav]

One last further question please. I notice the new Drayton ones just push on mines a older 1998 lifestyle one can I fit this to the valve? Thanks Paul