Not all radiators heating

[craynerd]

My grandparents asked me to put a towel rail heater in the bathroom to replace a radiator and chase the pipe work up the wall so the tiler can hide the pipe work. I've got a combi boiler so their vented system was new to me. I tied up the ball clock in the loft header tank, drained the radiators, move the pipes and end stopped the pipes - the tiler will tile then we will fit the new radiator. I untied the ball cock and turned everything back on.

Unfortunately, over half the radiators come on but 4 radiators do not get hot! I did something similar on my combi system and I didn't have anything like this - they all got hot.

After some reading, it seems like this could be correct! Have I broken a loop in a chain of radiators and therefore any rads in that chain wont get got, or does this sound like I have a problem?

Any help appreciated.

Chris
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[tincup]

Hi
Sounds like you may have an air lock.
Turn off the rads that work and see if the others warm up.

 

[craynerd]

Tincup, thanks for the info. If I turn off the working rads, will this hopefully solve the problem and remove airlock? - because I will not have access to the net when I'm at their house tomorrow, can I ask in advance, what do I need to do to get rid of the airlock...or what can I try and do?

 

[tincup]

When the system refilled its possible air got trapped in the pipes. Sometimes varying the pump speed can dislodge an air lock.

 

[scatmanjohn]

Did you bleed the radiators when you refilled the system?

 

[craynerd]

TincuP - I am unsure what pump it is and so I'll need to google how to change the speed.

reading more and more, I'm not convinced that I have correctly refilled the system. Googling "refilling" gives me hundreds of different methods of how to fill a system.

I read this on another forum, does that seem correct:

Bleed them all again, just to be sure and then turn off of all of the rads upstairs and downstairs bar one of the downstairs rads – this will be the first one that you are going to get working.

Switch just the heating on and confirm that the boiler comes on and stays on. After a short while you should be rewarded with some distinctive gurgling sounds from the one open radiator and heat will surge through very, very quickly. Leave it until you are certain that it is heating evenly and consistently and then open up the next downstairs radiator. When this is open, close off the first rad. Remember to bleed all of the rads in turn as the heat starts to come through. You repeat this process until all of the rads start to work. Then, open up all radiators and they will all work simultaneously.

Now turn the heating off and the hot water on. The hot water cylinder should have two 22mm pipes readily accessible. One near the bottom of the cylinder and one about a third of the way up. The uppermost one should be very hot and the lower one should be significantly cooler but still warm. If this is the case then the hot water circuit is working properly.

If this isn’t happening, look for a manual air vent in the airing cupboard and open it until water comes out if you find one.

 

[craynerd]

Did you bleed the radiators when you refilled the system?

Absolutely, I went around each radiator a number of times and bled them. However, it was quite random and there was no logic to my method! Just kept bleeding until water came out and no more air.