New Radiators Not Working

Hi Folks,

Using the boiler for first time this year in my house. Heating is coming on OK bar for 2 new radiators which arent heating up.

These 2 new radiators were put in by a plumber during the summer and are beside each other. The plumber did run up the boiler at the time and the 2 new radiators heated up fine.

I have turned the valves anti clockwise so the radiators should come on, also they are normal valves, not thermostatic.

Any ideas?

theteal

Any part of the new rads heating up? The pip leading to the rad heating?

Ubbquittious

Are they full of air?

Yes you were correct, air. Bled them and heat got into them. However, they might need to be balanced as it was never done whne addtional radiator was put in.. Other than that, the boilers pump may need to be dialled up a setting.

Update, these two new radiators are upstairs, valves fully open and bled. I 75% closed all other rads in the house to balance the system but these older radiators still heat immediatly, where the two new radiators take up to twenty minutes to get any heat into them. Any other ideas?

Roger the cabin boy

How far upstairs?

The attic?

spuddy4711

Try closing all the old rads, see if the new ones then heat quickly. I had a similar problem, caused by an airlock in the pipe to one particular rad, it took ages to clear. Find out the route of the heating, which rad heats first, second, then wind down the flow to these, allowing greater flow to the more distant rads. Assuming the new rads are at the end of the line. They heated well when first installed, so maybe an airlock is the problem.

https://www.boards.ie/discussion/comment/118163528#Comment_118163528

No the first floor, there is 4 rads on the first floor, 2 in one en suite room which are old and heat up immediatly, and 2 in other en suite room where the rads were replaced and thats where the issue is.

https://www.boards.ie/discussion/comment/118163538#Comment_118163538

I bled both these 2 new rads and have turned off all rads at one stage forcing it into the 2 new rads but still same issue, is it possible that an airlock on one of the old rads could be doing it?

10-10-20

Just checking here as it's not clear in the text - you are aware that there are two valves on each radiator? A lockshield valve and a "normal" or thermostatic valve? Also are you zoned to upstairs and downstairs?

The lockshield is a smaller screw or knob and is on the opposite side of the normal valve. The locksheild is used to balance the feed and return in the system by preventing the radiators nearest the boiler from taking all of the hot-water leaving the remaining radiators cold.

In your case please check that the lockshields on the new rads are approx 2.5 turns open (clockwise). Then I'd recommend that you go around to each radiator in the zone (upstairs) and place a mark on each valve knob and rotate each closed (anticlockwise), counting and recording the revolutions for each radiator. If your new rads then start working once all other rads in the zone are closed, then it was a balancing problem.

To re-balance the remaining closed radiators, re-open the valves to ~75% of where they were previously. If the new rads start cooling off, then close off each of the other rads by a quarter turn. Eventually you should get all rads heating up if it was a balance issue.

If you start hearing excessive air in the system, you'll have to bleed it again.

https://www.boards.ie/discussion/comment/118168473#Comment_118168473

No zoning, and yes have the lockshield valve on new and old rads. I have done this, and have all old rads in the system down to a 1/4 turn from fully open, with the 2 new rads fully closed (Anti), still no luck, I will bleed all the old rads to double check air in them isnt causing it, as I have bled the new ones.

John.G

Are these two rads of "normal" height ie not 5 or 6 foot tall?. Also a pair of new lock shield valves normally only have one that can be opened/shut with the plastic knob, the other has to be removed and a adjustable spanner used to open/shut the valve.

spuddy4711

In my case, the cold rad was removed and washed out, no heat. The pump was replaced, no heat. All other rads worked fine, like yours.

on a freezing winters day, the rad began to heat, and continues to heat. I, and 2 experienced plumbers, think it was an airlock in the

underfloor piping. Your two new rads worked well after installation, hopefully they will again soon. You could try varying the pump flow,

there’s usually a knob on the pump with 3 different settings. Give it a go.

10-10-20

https://www.boards.ie/discussion/comment/118170271#Comment_118170271

What happens when you bleed these new rads? Do you get a reasonable flow of water?

Well folks, got the rads going, a bit more bleeding was all that was needed, the balancing I done was OK, cheers for the help!