Hi

Just had a new boiler fitted in the loft and a radiator replaced downstairs (ground floor).
Some of the radiators work fine upstairs, whilst others don't at all. They have thermo valves on them, but these have been checked and pins raised to ensure hot water should get through.
All of them have been bled.
Downstairs is the same, one works really well, but the rest range from luke warm (the replacement one) to warm in parts.

The strange thing is, the bits where they are cold are at the bottom and/or middle of the radiator, not the tops.

Any ideas on what to do or check next please as it's winding me up now, esp as its so frickin cold at the moment?


Cheers

I'm not a plumber, so they may be a better solution...

Have you tried adjusting the lockshield valves (the one at the other end from the 'stat valve), the system might need re-balancing.

HTH.

John.

Looks like a flow problem.

Are you SURE the pump is running? (Remove centre silver cap, check that spindle is going round).

Have you checked there is nowhere for air to get into the system? (Is the expansion tank full?)

OK, now switch off pump, go round and close ALL lockshield valves) the ones on the other end of each rad to the TRV's) with an adjustable spanner. Turn pump on at slowest speed for about 30 seconds. Turn it off again.

Open the ones in the bedrooms a full turn, no more. Open the ones in the lounge etc downstairs about half a turn, no more.
Recheck what happens now with pump running at normal speed.

Oh, and when you bleed, you DO turn the pump OFF don't you?

Alcazar

Thanks for the replies guys.

Looks like rebalancing is the answer. Would this still be the case if the pipes are hot running right up to the TRVs?

Alcazar - Oop! I think I've failed on every count mate. Being a complete DIY dunderhead I haven't got a clue about expansion tanks and turning off pumps.

Are you referring to the pump on the boiler? How/where do I check the expansion tank?

Sorry to sound a bit daft here. Once I know the above I will give your suggestions a go.

Much appreciated :thumb:

Hi

Just had a new boiler fitted in the loft and a radiator replaced downstairs (ground floor).
Some of the radiators work fine upstairs, whilst others don't at all. They have thermo valves on them, but these have been checked and pins raised to ensure hot water should get through.
All of them have been bled.
Downstairs is the same, one works really well, but the rest range from luke warm (the replacement one) to warm in parts.

The strange thing is, the bits where they are cold are at the bottom and/or middle of the radiator, not the tops.

Any ideas on what to do or check next please as it's winding me up now, esp as its so frickin cold at the moment?


Cheers
Put your heating on full on the wall stat,turn off the rads that are working and this will push the heat to the other rads.After they are hot turn the other rads back on.If this fails call back who ever fitted the new boiler and get them to sort it.I wouldnt bother trying to balance the system as turning lockshield valves that havent been moved for a long time usually causes the glands to leak.

Thanks Mattsan, I think I'll try that first then.

You're right, the boiler fitter should get his ar$e back in here and sort it really.

Cold spots on radiators indicate a sludge problem. Did your installer complete a flush of the heating system before installing the boiler? Manufacturers now state this as a requirement when installing new boilers and also state that not doing so voids any warranty....