Radiators not heating up

[cbrand]

Hi, I have a problem where different radiators are heating up to different temps and one radiator not heating up at all. I have bleed all the radiators so no air in them. I have also made sure that the radiator taps are open and on max on all the radiators. I have 6 radiators in my flat, the one in the hallway is operating "normal" and hot, the one in the back bedroom does not warm up at all and the other 4 only slightly warming up. What could be causing this strange problem please?

 

[easyflow]

Go to frequently ask questions and look at balancing.

 

[cbrand]

Thank you.. is the lockshield valve on the left hand side of the radiator as you look at it?

 

[terryplumb]

It can be on any side ,and may differ from one radiator to another.

 

[cbrand]

how do you tell the difference, is the warmer pipe the water coming in?

 

[terryplumb]

Yes ,the pipe that heats first is the flow ,lockshield should be on the return.

 

[cbrand]

Thanks.. wll give it a try

 

[cbrand]

None of my radiators are getting hot enough and only tops of them are getting hot along with the area near the pipe where the heated water is coming through.

I am guessing I need to flush the radiators, as I have already bled them and balanced them.

There is a draining point below the radiator in the bathroom. If I isolate the boiler and drain the radiators using this drain point, would that work, clearing all the water out of them and any muck etc?

Or would I need to isolate the boiler, take off one of radiators and hook to the tap and pump water through the radiators one by one by isolating all the radiators and only opening one radiator at a time?

Any help and advice would be greatly appreciated.

Thank you

 

[terryplumb]

Is your central heating by a combi or system boiler ? You mentioned in earlier post ,that one radiator never gets hot . is that still the case ? If so ,does it have a thermostatic valve that may be stuck in the closed position.
If you think the system needs a clean out ,first introduce a chemical cleanser ,and let it run for a while in the central heating system ( varies in time but several days minimally ) . After the cleanser has had time to work ,then do the flushing out .

 

[cbrand]

I have a combi boiler, an baxi combi 80E, I sorted out the issue with one of the radiators not getting hot by balancing the radiator as suggested earlier.. so all the radiators are heating up now.
I have observed that the radiators are not fully heating up, on the tops of them are hot, at the bottom and middle of the radiator it is warm.
Any suggestions of what chemical cleaner to use and how I introduce it into the central heating system?
Thank you for your help.

 

[terryplumb]

Fernox F3. Can be introduced via a radiator. If you have a towel rail type radiator ,with the air bleed valve on the top thats ideal. You need to drain water out the radiator first .when thats done remove the bleed valve and pour in cleaner via a funnel. Refit bleed valve and top up system pressure. Can be done on a conventional panel rad ,with bleed valve on the side but a little more awkward.

 

[wijcc]

Thank you. I don't have a towel rail type radiator, I only have the standard rectangular panel radiators.

Do I need to only isolate one radiator, drain it via the bleed valve and fill it with the Chemical cleaner? Also topping up the system pressure is done on the boiler in the usually way, when the pressure on the boiler tops?

Additionally with regards to flushing the system.. do I need to isolate the boiler, take off one of radiators and hook to the tap and pump water through the radiators one by one by isolating all the radiators and only opening one radiator at a time

Thank you again.

 

[terryplumb]

Use the drain cock on your bathroom rad to empty water out the system ,then add the cleaner and top up your pressure. Once the system has been ran with cleaner in for several days. report back on results.

 

[cbrand]

I drained the system using the drain cock, added the cleaner to the radiator and re-pressurised the system. Bleed the radiators.
I have put the heating on but it is not getting hot, the flame is not coming on, the boiler seems to making the right noises. The pump is spinning and hot, the pressure rises on the boiler.
If I put the hot tap on, hot water comes out and the boiler flame comes on for a bit then goes off.
What do I need to do to get the heating to be working again... The heating came on fine, before I drained the system???
Thank you.

 

[terryplumb]

Do you have a wall thermostat ?
What is the system pressure ?
When turning a hot tap on ,letting it run continually ,does the boiler give you continuous hot water ?