3 new radiators all half cold since installation

[pinheadplanet]

Hi

I've just had 3 new rads fitted onto my central heating system (halsted ace high boiler) but all three rads only get hot at the top (or along one side on the vertical rad) so if i try to bleed them no air comes out, just water.

I've tried banging the rads to release any air inside but i'm not sure it's doing anything.

Pressure is maintaining at about 1.3 bar.

I don't think the guy that installed them put any inhibitor in when he finished the installation but I guess this shouldn't make any difference.

What am i Looking at to resolve the problem? I've paid a lot of money for the three rads and it doesn't make any sense to only be getting half the output from them.

Cheers

 

[tomy]

How about getting your installer back to sort it out

 

[pinheadplanet]

well yeah, but be good to know what i might be talking about before he comes back.

 

[MANDATE]

If they get hot at the top, thats tells you they don't need bleeding.
you've not mentioned balancing and that is most likely the solution.

 

[pinheadplanet]

well funny you should mention that.

I got the feeling he didn't balance the system after he installed the 3 rads.

How do you balance the system?

 

[smiffy47]

They've explained it all for you here

http://www.diydoctor.org.uk/projects/balancingcentralheatingsystems.htm

Do a search on the site/forums next time. Many questions such as this have already been answered.

Most of the time the info I need is already available & I don't need to post needlessly.

Mike

 

[reneel]

just a thought after reading this post, if they are new rads added and not just replacment for older rads, then possibly the boiler's KW output isn't enough for 3 more rads?? just a thought? other than that it's probably 99% that the system isn't balanced yet !

 

[pinheadplanet]

I checked with the boiler manufacturers and I am nowhere near my total boiler output.

 

[pinheadplanet]

UPDATE

The installer came back, turned off all the other rads in the house in an effort to 'push through' any blockage in the three rads that weren't fully working.

It seems to have worked on two of the rads but the last it totally hasn't, so I still have only half my output from that rad.

The Installer said 'leave it for a while and see what happens'. Personally I don't think anything is going to happen on it's own...

As for Balancing the system he said 'you don't need to balance the system because I have thermostatic valves on each rad and therefore I just set it to whatever temperature I want and then the rad turns off when it gets up to temperature. Doesn't sound right to me. What do you think?

 

[namsag]

He is talking nonsense the system still needs to be balanced even with trvs on it. Try turning everything else off to force any remaining air out of the pipework to the offending rad.

 

[pinheadplanet]

Yeah that's we've done, turned off all the other rads but it's not worked.

What next?

 

[superdupergasman]

make sure the lock sheild valves are opened up enough, no flow, no heat.

should be enough half way, but depends if they are on the flow to the rad or the return.

Feel which gets hot first, if on the flow then might be worth opening them further than half.

 

[yerino]

1) turn off the thermostatics on ALL your other radiators.
2) wack your central heating up to the max on the room stat
3) make sure both valves on the cold rad are opened up to max
4) leave for an hour and should be sorted.

post back if any probs. he might have just tee'd into the old existiing 15mm pipe to run to the 3 extra rads. hence not enough water gettin through.

if all fails. call him back and say balance them. they need it!!

 

[pinheadplanet]

We've tried that already.

I am trying it again as I've been away for a few days and it seems the 3 rads are all not heating up equally overall the surface of the rad, specifically the bottom isn't getting hot.

The Lockshields on all three rads installed are already set at fully open by the installer.

I'm gonna leave them all on max and have turned off the rest of the house and see what happens, let you know in a while.

 

[pinheadplanet]

Well nothing's happened with the rads,

But I have spoke to the radiator manufacturers Runtal and they told me this about installing rads.

It is imperative that they are all balanced to achieve the correct flow rate.

When installing rads you need to close off both the TRV and the Lockshield, open the air vent/bleed valve and then slowly refill the rad by opening the TRV, this pushes the air in the rad out through the air vent. Once water is coming out of the air vent close it off and open the lockshield.