Advice needed - faulty heating programmer or something else?

[terryplumb]

How long have you lived in the property ?
Did living room rads work this time last year ?

 

[grumpypj]

yes they worked last year.

 

[terryplumb]

What did you do to them in the summer when you had some rads coming on when programmer was not calling for heating ?

 

[grumpypj]

used the trvs on all rads to turn them off..

 

[terryplumb]

I assume your system is pressurised ,does boiler have a pressure gauge ?
If turning off EVERY rad including towel rads ,and just living room rads ON doesn't result in the living room rads heating ( with programmer not calling for domestic hot water ,only central heating ) Then the living room rads valves are suspect.
Are you certain the living room rads lockshields were not / are not closed ?

 

[grumpypj]

I assume your system is pressurised ,does boiler have a pressure gauge ?
If turning off EVERY rad including towel rads ,and just living room rads ON doesn't result in the living room rads heating ( with programmer not calling for domestic hot water ,only central heating ) Then the living room rads valves are suspect.
Are you certain the living room rads lockshields were not / are not closed ?

@terryplumb - the boiler has a pressure gauge, i am including a picture. The boiler is a vaillant one

I tried to figure today how to turn towel rails off. there isnt a TRV on the rails. On either side of the towel rail there are two white caps which I can move clockwise and anticlockwise. are these the switches to turn the towel rail off? we have never turned towel rails off as during summers too we like towels to be warm. Because i dont know how to turn towel rails off I was not able to do the troubleshooting you mentioned.

finally on the lockshield - i tried to free the valve its jammed up like hell. Also it is not a hexagon-ish shape that i see on youtube videos. ours has a screwhead and with a screwdriver there is no way i can move it. picture attached. Shall i try to get a Wd 40 style lubricant and try? Also - should i try to move this with a scredriver or pliers?

 

[grumpypj]

also given that this valve won't budge, i feel it could well be stuck..If you look at the picture, you will see it hasnt been touched in ages and has this greenish-white tinge to it

 

[sxturbo]

To adjust that valve you need to undo the nut using a spanner first and then rotate the screw.

I doubt this is the source of your problem, unless it is block with debris.

The bathroom valves, turn them clockwise to close, and anti clockwise to open.

The flow to the towel Rad should be fully open, and the return should be open around a quarter turn (might be more or less when balancing the system properly), however when experimenting just close the return only.

It is most likely a faulty trv valve siezed in the fully closed position causing the rad not to heat. The trv head pushes down to close the valve.

In regards to the heating being on with the hot water, have you confirmed whether you have a Y plan system yet?

 

[terryplumb]

As the living room rads worked last year, and you obviously have not closed their lockshields ,they can be ruled out ,unless there is a blockage,which is unlikely on both living room rads.
The two towel rads need one of their valves closing. A pic would be good ,but your description sounds like a wheel head. They close by turning fully clockwise.

 

[grumpypj]

As the living room rads worked last year, and you obviously have not closed their lockshields ,they can be ruled out ,unless there is a blockage,which is unlikely on both living room rads.
The two towel rads need one of their valves closing. A pic would be good ,but your description sounds like a wheel head. They close by turning fully clockwise.

@terryplumb :
pictures of towel rails attached from both bathrooms, seems identical set up in both bathrooms. On either side of the Towel rail, the white caps ARE moving. Let me know which one I need to turn clockwise.

And you are right sir , we have not touched lockshield or TRV ..I didnt know the word 'lockshield' till last evening when it was mentioned on this thread Let's do this experiment. After this TRV should be the only thing left i suppose.

@sxturbo : I am afraid that link didnt make it clear to me how to determine if i have Y plan. on that link it seems I will have to compare the circuit diagram to the installed circuit in my house. The wires are hidden behind the vaillant boiler cover etc. are you suggesting that i take the cover off somehow and compare?

 

[grumpypj]

one question though...TRV is likely to be the "In" water flow to the radiator, right? If that's the case, when I bleed the radiator, should i see water coming out? I bled radiators last evening and both radiators had plenty of water coming out of them. water wasnt warm though.

 

[sxturbo]

Do you have a valve like this in the heating system, usually near the hot water tank

https://www.toolstation.com/corgi-3...at8A7Hu2zu6e_USyK1tyZLI2-jVRU_okaAlDvEALw_wcB

You need to replace the trvs on the radiators in the living room, they are stuck shut.

The towel rail..

The pipe that gets hot first should be fully open (counter clockwise), the pipe that is cooler, heats up later should be almost fully closed, opened by 1/4 turn

 

[sxturbo]

one question though...TRV is likely to be the "In" water flow to the radiator, right? If that's the case, when I bleed the radiator, should i see water coming out? I bled radiators last evening and both radiators had plenty of water coming out of them. water wasnt warm though.

They would be pressurised from the return flow.

The trv is usually fitted to the flow (hot) pipe

 

[Harry Bloomfield]

one question though...TRV is likely to be the "In" water flow to the radiator, right? If that's the case, when I bleed the radiator, should i see water coming out? I bled radiators last evening and both radiators had plenty of water coming out of them. water wasnt warm though.

That depends on the TRV model. Some can be fitted to flow or return, others only to flow.

As you bleed a radiator, water can enter the radiator via flow, return, or both. The fact you have water coming out, is all you need to know, to be sure there is no air in the rad.

 

[terryplumb]

You can close either of the valves on towel rads. Do the left hand valve on each towel rad ,and make a note of how many turns it takes on each . That will enable you to open them,later on , back to their original positions.