Why does downstairs heating has to be on for upstairs to work?

[Husk24]

Hi All

I have a question regarding my heating setup, I moved in 5 years ago and since replaced boiler and added 3 nest controls. I have a system boiler with water cylinder and have three nest thermostats, one controls and turns on the boiler for downstairs apart from the conservatory where I have another nest , that only works when the downstairs heating is on and I can see a valve for that near the boiler.

my issue is upstairs, I can only heat upstairs with downstairs being on, I have to have downstairs turned on , if I operate the upstairs nest thermosta it doesn’t switch the boiler on without turning downstairs thermostat on. When I had my boiler replaced/installed , the engineer did try to source the valve for upstairs but couldn’t find if there is such a valve anywhere, it’s definitely not near the boiler where the main and conservatory valve is.

can anyone shed some light in this? Is there potentially a hidden valve for upstairs? Or is there a need for some repiping to separate the zones or could it be just an electrician installation that needs changing?

thanks

 

[Chuck]

I don't think you have a missing zone valve, I just think this was an S plan system that was extended rather poorly.

It may have been by this way by design. The whole house was probably once controlled by a single thermostat downstairs and the upstairs zone valve would be shut during the daytime period when it was not required by a simple time switch. This arrangement avoids the need to have a thermostat upstairs and works surprisingly well. In particular, it reduces the short-cycling that tends to occur with relatively small zones calling for heat independently.

 

[Husk24]

It may have been by this way by design. The whole house was probably once controlled by a single thermostat downstairs and the upstairs zone valve would be shut during the daytime period when it was not required by a simple time switch. This arrangement avoids the need to have a thermostat upstairs and works surprisingly well. In particular, it reduces the short-cycling that tends to occur with relatively small zones calling for heat independently.

It may quite possibly be that, my house was built 30 years ago detached house.

So if there is no valve what is switching the upstairs heating on? what controls the heat or water to heat the radiators upstairs?

 

[exedon2]

Fairly sure there is a valve for Bedroom zone otherwise it would work whenever downstairs was on.
Its probably just wired to be turned on and of by stat ie no switch wires connected.

 

[Timmy D]

Fairly sure there is a valve for Bedroom zone otherwise it would work whenever downstairs was on.
Its probably just wired to be turned on and of by stat ie no switch wires connected.

With this in mind (valve added at some point to turn off upstairs heating), a switched live from the zone valve was never run to the boiler due to the difficulty.

As it’s likely that the valve is just being controlled by a stat, I wouldn’t be surprised if the stat has independent power (check with multi meter).

If the above is correct, it’s also likely that the zone valve is close to the stat and or a power source.

I’d be looking on the same floor/perhaps room as the stat for a concealed access in the area you suspect the flow and return to be.

 

[Husk24]

With this in mind (valve added at some point to turn off upstairs heating), a switched live from the zone valve was never run to the boiler due to the difficulty.

As it’s likely that the valve is just being controlled by a stat, I wouldn’t be surprised if the stat has independent power (check with multi meter).

If the above is correct, it’s also likely that the zone valve is close to the stat and or a power source.

I’d be looking on the same floor/perhaps room as the stat for a concealed access in the area you suspect the flow and return to be.

Thanks for the reply, the stat is in the utility room next to the the downstairs stat so I am going to see if I can find something somewhere, the utility room is attached to the garage and the garage has a loft and I have yet to check there. I can see pipes going into the garage loft so maybe thats how the pipes go upstairs and the valve could be in the loft, I shall see if I can find anything in there or anywhere near the utility room.

 

[Chuck]

I shall see if I can find anything in there or anywhere near the utility room.

If you have some means of turning the upstairs zone on and off, get someone with good ears to wander around listening for the sound of a motorise valve operating while a helper turns it on and off.

When I moved into my current house it took me about half a day to find a pump. It turned out to be in a section of the roof that the previous owner had borded over with sheets of chipboard leaving no access and no record of what was hidden beneath. It was also a very quiet pump...

 

[Husk24]

If you have some means of turning the upstairs zone on and off, get someone with good ears to wander around listening for the sound of a motorise valve operating while a helper turns it on and off.

When I moved into my current house it took me about half a day to find a pump. It turned out to be in a section of the roof that the previous owner had borded over with sheets of chipboard leaving no access and no record of what was hidden beneath. It was also a very quiet pump...

Well i can control my thermostat on my mobile so easy, I have tried briefly but no luck, plus I guess it needs to be really quiet in the house lol
[automerge]1606000706[/automerge]

Well i can control my thermostat on my mobile so easy, I have tried briefly but no luck, plus I guess it needs to be really quiet in the house lol

Also wouldn’t it be easier to also follow the pipe that is potentially going towards upstairs?

 

[Chuck]

Also wouldn’t it be easier to also follow the pipe that is potentially going towards upstairs?

Yes, but I assume you've already tried that. My 'listen carefully' method is, however, easier than taking up floors and endoscoping cavities...

 

[Husk24]

Yes, but I assume you've already tried that. My 'listen carefully' method is, however, easier than taking up floors and endoscoping cavities...

I am planning to spend some time investigating this today, will try the ‘listen carefully’ method and I hope I am successful, Im I right that the missing valve should be the same as the the valves near the boiler? The noise those make is pretty obvious

 

[Chuck]

Im I right that the missing valve should be the same as the the valves near the boiler?

It may or may not be identical (how would I know?) but it'll probably sound somewhat similar, i.e. a small motor running for a short period and maybe a clunk at the start and/or end of the travel. If it's a pump rather than a valve it'll running continuously while the zone is active and stop when it's not.

 

[Husk24]

It may or may not be identical (how would I know?) but it'll probably sound somewhat similar, i.e. a small motor running for a short period and maybe a clunk at the start and/or end of the travel. If it's a pump rather than a valve it'll running continuously while the zone is active and stop when it's not.

No luck, tried following pipe , listened to noise every room upstairs, no luck im afraid