Radiators not heating

StevenPac79

Hello! So I had a new radiator fitted in a garage conversion, and I found that it wasn't heating like the other nearby radiators in the hallway and kitchen. The plumber adjusted something and now I find that the new radiator heats up but the hallway and kitchen barely get warm. I don't use this plumber anymore, but is there an easy way i can redirect water flow to the other rads? I assume he's turned a valve or two and so the new radiator is getting all of the flow. Any ideas what on the radiators I can turn to adjust this? thanks

nofoollikeold

1. Virtually every radiator has two valves, one at each end:
1a. One is either adjustable via a plastic knob on top (a wheel head valve) or is a Thermostatic Radiator Valve (TRV).  This can be adjusted to make the radiator cooler or warmer.  
1b. The other is not adjustable via a knob.  The cap will pull off or unscrew, revealing a spindle with flats on it.  This spindle can be turned with a spanner, grips, or, in extremis, pliers.  This is the lock shield valve, and is used to adjust the flow of water through the radiator.  
2. By adjusting the flow through each radiator, the system can be balanced, so that each radiator dissipates into the air the right amount of heat from the water flowing through it. 
3. It might be that adjusting the flow through the kitchen, hall and extension radiators, you can achieve what you want.
4. However it might be that:
4a. The whole system needs rebalancing.  There are various videos / faq's on the internet to help with this tedious task.  
4b. The extension radiator has been tapped into low diameter (15 or 10 mm) pipework and the the pipework cannot carry the amount of heat required to bring the radiators in all three room to temperature at the same time.  The only remedy is to rerun pipework.

StevenPac79

Thank you for your wonderful explanation. I will try adjusting the spindle and see if I can rebalance that end of the house. 

I know that when the conversion was done, he ran new pipework from the hallway rad area across the garage to the new radiator. He seemed to suggest previously that it was just a case of balancing it, but he seems to have only managed one or the other. I'll have a play around and see if I can rectify it. Thanks

Jeepers_Creepers

As nflo says.

As a quick test, turn down/off the new rad - do the hallway and kitchen rads now heat up? If so, it is likely just a balancing issue as said before.

You might be able to tweak this new rad down so that it still works but also doesn't steal the flow from the hall&kitch rads, but it might also be that this trio of rads actually need a little extra flow in general from the whole system. Ie, as nflo says, it might all need balancing. 

Do you understand the difference between the two valves on each rad - one is 'temp control' and the other is 'set and forget for balance' = 'lockshield'? Cool. In which case you can try this to give us some info to work with:

On each of these three rads in turn, remove the plastic caps from the lockshield ends (this is the 'balance' control) and you'll likely find spindles underneath which have 'flats' for a spanner on top. Ok, first turn each one clockwise to shut them off fully. Important - count the number of turns and part-turns this took. Note that down for each, and let us know what they are. Now return them all to that setting until we can get back to you :-). 

stragglebod

nofoollikeold said:

1a. One is either adjustable via a plastic knob on top (a wheel head valve) or is a Thermostatic Radiator Valve (TRV).  This can be adjusted to make the radiator cooler or warmer. 

TRVs set the room temperature at which the radiator comes on. The radiator is either on or off.