New radiators not heating up

greenbee

I recently had two new radiators installed (one a replacement, one completely new), with some of the 15mm pipework replaced with 22mm back to the landing (where the 15mm will be replaced in a few weeks when the landing floor can be taken up). At the same time a new dual fuel towel rail was put in to replace an electric one. The plumber installed it, repressurised the system, and went off on holiday. Pressure dropped (there are vents in the attic), I bled the radiators, repressurised, bled the radiators, and topped up again. 

All the other upstairs radiators (6) and the old and new towel rails are working fine. Both the new and replacement radiators have water in them, but aren't heating up - and the inlet pipes aren't getting warm. I can't get my head round how they can have been filled with water but not heat up with the rest of the upstairs radiators - they are on pipework that served the original radiator, and the towel rail also comes off this.

I'm pretty sure the plumber is back from holiday as this week was one of the options for him to do the work. He's read my message but not replied (he's always rubbish at responding, and I probably asked too many questions in one go as I need to book him for the next phase of work in order for everyone else to know when they are doing stuff), and I need to know whether to delay the carpet fitting. 

Is there anything else I can try while I wait for the plumber to get back to me?

molerat

Either an air lock or the system needs balancing.

bjorn_toby_wilde

Maybe way off beam but have you checked that the lockshield valves are open?

The only thing I can think is that it’s still possible for you to be able to bleed the rads if the TRVs were open but there wouldn’t be any flow if the lockshields were closed.

greenbee

Thank you both - yes, we've checked the lockshield valves, but I'm wondering about fully opening them at both ends and shutting down all the other upstairs rads in an attempt to get them to heat up... I seem to remember having done this in a previous house.

As the weather is going to be vile tomorrow afternoon, I think I'll spend some time on it then. I know they'll need balancing as plumbers never seem to bother (and it's a big house, so a PITA to do without lots of friends to help work out which order they heat up in!). I must remember to WRITE DOWN the order of the radiators once I've worked it out!

WIAWSNB

Did the replacements ever heat up, even immediately after installation?
Obvs thing to try - shut off the other rads. Do these two now heat up?

greenbee

WIAWSNB said:

Did the replacements ever heat up, even immediately after installation?
Obvs thing to try - shut off the other rads. Do these two now heat up?

The boiler wasn't on when they were installed - he didn't turn it on to test, just repressurised (it was a struggle to fit the job in before his holiday, but it had been booked for ages, and there were other trades booked so he had to get it done). With everything else going on, I didn't get round to testing until the last couple of days.

We'll try shutting down all the other rads tomorrow. I'm not up to climbing over piles of furniture in the rooms we've moved stuff into right now. 

WIAWSNB

Not all other rads need turning off - just the ones you can reach easily

If the new rads now heat up, it'll likely be a case of the system needing rebalancing. Or, if an airlock, it will hopefully shift it. 

MysteryMe

He really should have checked the rads were heating up before leaving (and you paying)