Help....Question on radiators

[mumtosp]

Hi all,

This is going to sound stupid, but I need help figuring out how the radiators work in my house !! We've moved into a rented place - which is a big old house. The radiators in the downstairs room have all been replaced with new radiators and I need help figuring out how the valves work..

So we have a boiler and a central thermostat in the hallway. All the downstairs radiators have 2 valves - a big one with numbers from 0 to 5 and another smaller one with just a + and - sign.... so how do I use the 2 valves?

Now all the radiators upstairs are old and don't have a big valve with the numbers from 0 - 5. It just has the small valve with the + and - signs. So how do those work ??

Sorry if it's a stupid question... I've always lived in flats with electric heating. This is the first time I've come across these type of radiators...

TIA :)

the + & - ones are the water inlet I think; so you'd turn it to - if you needed to cut the water off

the 0-5 ones are thermostatic, & if set on a low number the rad will stop heating up once the room reaches whatever temp that matches

(some of ours have them & the default setting seems to be 3, but if it's a room that always feels cold you could turn it to 5. & vice versa)

disclaimer - I am very much not an expert!

I hope you have a room thermostat as well?

the room stat should turn the heating on and off depending on how cold it is, and subject to the timer, and the rad valves adjust relative temperatures within the rooms.

the room with the room stat should not have a TRV, or they will conflict, and its radiator should be adjusted to warm up slower than all the other rooms, otherwise the room stat will turn off the heating when other rooms are still cold.

If you have bought the house, consider changing to TRVs in the remaining rooms when you have the money or want to do some DIY plumbing. Do your plumbing in early summer, when the heating will not be needed.

Old TRVs often jam.

there will be a lockshield valve on the other end of the radiator, probably with no knob. Do not interfere with this until you have read about balancing radiators.

Thanks Ponders ... you may not be an expert, but you know more than me :)

PigletJohn... that was a lot of info (not sure I understood all of it)... but thanks :)
To answer your question.... we do have a room thermostat and it's located in the hallway just outside the kitchen. There is a rad in the kitchen which is close to the entrance and hence very close to the room thermostat, but as you said it doesn't have a TRV.
However, there is another rad in a hallway itself and that one has a TRV.

For the rooms which don't have a the TRV valve, but just the +/- valve how do I adjust the heating?

Thanks again :)

let the heating run, using the room stat to automatically switch it off (like an oven thermostat if you were baking a cake, you find the right setting and don't keep changing it or turning it on and off)

See which rooms are a bit too hot, and turn the rads down a tiny bit. See which rooms are a bit too cold and turn them up a tiny bit (when this fails, turn all the others down, when that fails, fit bigger radiators in the cold rooms.

When you are balancing radiators, turn then all the way down, then open just half a turn. Wait an hour and if necessary adjust them another quarter turn. Almost all the adjustment is in the fractions of a turn from the closed position. this adjustment should be done on the "lockshield" valve, and once you have got it right, you take the knob off to prevent anyone destroying all your careful work.

If you search "balancing radiators" you will probably find it explained better.

like this

you will not have pipe thermometers, so when a radiator is on, the incoming pipe should be "too hot to hold" and the outgoing pipe should be "too hot to hold for long"