heating problem!

[ih]

my system is the following.
boiler conventional potterton profile 100e
programmer honeywell st6400c
valve V4073A1039
pump Grundfoss super selectronic 15/60
room thermo honeywell T6360b1028
I will appreciate any help advise on the following 2 problems.

1. When i request Heating via the extra hour button on the programer it could be anything from 10 minutes to 25 minutes before the boiler kicks in. (However when i request hot water the boiler kicks in same time)
2. With the heating switched OFF and only hot water ON i find the upstairs room radiator which has trv gets hot on the top?
Thanking in advance
ih

 

[uselessFCUK]

1. When i request Heating via the extra hour button on the programer it could be anything from 10 minutes to 25 minutes before the boiler kicks in. (However when i request hot water the boiler kicks in same time)

- Have you checked what your room stat is set to? Maybe too close between actual temp and desired temp.! Turn it up til it clicks then monitor how long to fire up the boiler.

- Have you investigated whether this occurs during normal heating period?

It could be the mid-pos valve sticking therefore 'dragging it's heels' in getting over to switch the microswitch in order to tell the boiler to fire.

2. With the heating switched OFF and only hot water ON i find the upstairs room radiator which has trv gets hot on the top?

Perhaps the mid-pos valve letting by when in the DHW position.

 

[ih]

thanks for the reply
the room stat is well set to call heating. by this i mean the room temp is 18/19 degree and u turn the stat to say 25 degree. even then the boiler does not kick in instantly
--- this happens in normal heat period

1. How do i correct the sticking valve ?
2. How do i address the issue of the valve letting dhw
3. If i replace the valve will this solve both problems or does the programmer needs seen to.
thanks

 

[uselessFCUK]

Try this:

- drag the lever on the valve over to manual and switch on CH only.

See if the boiler fires up straight away.

Regards
UF

 

[ih]

thanks for reply UF
Yes on setting the valve to manual and cal for CH the boiler fires straight away[Will appreciate if somebody out there can conclude and advise what i need to do to solve the two problems .
thanks in advance.

 

[uselessFCUK]

Hey up

I can't spend your money... but if it was my own I'd replace the valve complete!

You'd be looking at a drain down and electrical isolation, and at least £45 (or possibly less on ebay) just for the complete part, then there's the option of a pro fitting it!

Please don't accept my advice alone!

There's experienced pros here that could "theoretically" confirm these symptoms. Perhaps the valve mechanism within the valve actuator can be adjusted in part, maybe that's sticking so not actuating the valve to fully close off the CH circuit.

Regards
UF

 

[baxpoti]

I'd replace the valve complete!

So would I.

The actuator head is available as a separate spare, but as it's warming upstairs rads, it would be false economy.

 

[ih]

Most grateful to UF and thanks baxpoti. Advise/help appreciated.
Will replace complete valve it has been good for nearly 10 years.
thanks again
regards
ih