Odd Radiator behaviour?

[ETHunter]

Good morning, I wonder if someone is able to help out here. I have noticed over this cold snap that a number of my radiators do not seem to heat up properly. They are very hot at the bottom where the pipework is and about 350mm up the radiator, then it cools rapidly and there is virtually no heat being given off at the tops. Is someone able to tell me the cause of this and how it can be corrected, or should I just call a plumber?

MOD 2

if this is a wind up it goes

 

[masona]

Have you tried bleeding them from the top of the radiator bleed vent?


Edit: spelling error

 

[ETHunter]

Masona, many thanks for the reply, but how do I bleed the radiator? I am sorry if this sounds like a stupid question, but I am not a hands on worker or know anything about the way this stuff works. I know that at the top of my radiators there are square type plugs that are inside a large nut that appears to be a cap on the radiator, and at the bottom the radiator is plumber onto the pipework. I am aware there is a system bleed tap outside my front door. Do you mean I need to open this tap and drain the water out to change it?

FAO Mod 2.

Your logic escapes me, I have a question I need an answer too and you question it, I was under the impression that this was a DIY forum for asking such questions. Am I incorrect in this assessment?

MOD 2
my logic is based on your behaviour in general chat

 

[kevplumb]

you need the second bit to undo the first bit and let the air out

 

[ETHunter]

Arh, Kevplumb, thank you for your post. I would assume that such a tool can be purchased from a DIY shop so I shall get myself into Chemsford and buy on from B&Q.

How do I know when all the air is out?

 

[kevplumb]

How do I know when all the air is out?

err just a wild guess the water comes out instead

btw if you have a sealed system (pressure gauge on boiler) you will need to top the pressure up (faq at the top)

 

[Softus]

How do I know when all the air is out?

Water will start coming out.

Make sure the pump is not running while you're venting, or you might draw air in instead of let it out.

 

[ETHunter]

kevplumb, Yes that makes sense, that is the trouble when you know nothing about such things, you ask questions that when you get the answer seem so darn obvious. I shall check the Faq. Once again, thank you for your help.

 

[ETHunter]

Went to B&Q, bought the tool required, cost a massive £2.99, came home and followed the advice. Radiator hissed for a while, when water came out I locked the valve again and repeated this with the 4 radiators I had this problem with. Now all are hot at the top as well as the bottom.

I would like to say a big thankyou to Masona but especially kevplumb for their advice, but also any member who has contributed to the faq section. I am not one for DIY, but such a simple task, when you know how, is easy to do.

 

[Softus]

Radiator hissed for a while, when water came out I locked the valve again and repeated this with the 4 radiators I had this problem with. Now all are hot at the top as well as the bottom.

If you had to vent that many radiators then there's a strong possibility that your system is corroding internally.

It would be sensible to determine the extent of the corrosion and to undertake some simple preventative maintenance - look for "inhibitor" in the FAQ section.

 

[Slugbabydotcom]

Went to B&Q, bought the tool required, cost a massive £2.99

You were well ripped off there. Am I out of date or are they still a quid anywhere. I'd spend another £20 worth of time and a tenners diesel getting a better price just for the pleasure of going back to BnFnQ and sticking it up their price promise.

I did it to them once over a grundfos pump after they upset me once. I went to a merchant and got a trade price of about £38 then walked into BnFnQ and got a further 20% of the £38. They were selling them at about £49