Cold radiator

T

theoaks

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The radiator in the downstairs toilet(furthest away from the boiler) is stone cold while all the others in the house heat up fine.The pipes coming into the rad are also cold, I tried balancing but without success. Pressure in the boiler was down slightly but have increased this and still no joy,It was fine until recently. I suspect an airlock,does the system need to be drained?
 
Hi I also have an issue with a radiatot that is cold at the bottom only when all others in the house are fine .There is no air coming out if I bleed it which usually happens when they are cold at the top .
Any ideas whet might cause this
 
If you turn off your other rads and you still have no heat, then it would suggests you have circulation problems, which could be anything, normally sludge less likely air if you have a pressurized system.
If the bottom of a rad is cold then the normal reason would be sludge which has a sandy Consistency and settles on the bottom of rads and pipes.
 
Many heating systems cannot be balanced or powerflushed properly because there is no gate valve (balancing valve) on the primary return pipe from the hot water cylinder.
 
(If valve is missing)The solution is to ask a competent plumber to fit the missing balancing valve.
Many householders only think about correcting a heating installation when they are trying to sell a house
 
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I have a similar problem with three of my radiators. They are warm at the top but cold or cool at the bottom. The inlet pipe (which happens to be at the lockshield valve end on my system) is hot, the valve itself is hot and so is the round golf-ball sized piece of metal between the valve and the radiator panel (there is one of these at each of the four corners). The rads are called "Heatmaster". The system is six years old. It looks as if hot water is getting to the rads (ie no blockage in the inlet pipe or valve) but not heating them fully. Any ideas what might be causing this phenomenon?
 
If ground floor radiators only are not working then you may have faulty circulating pump
Otherwise refer to my previous posts

Or study plumbersdiary.com with your plumber
 
One of the dodgy rads is upstairs. It's a double rad which heats up on one panel only! The others are downstairs. But this may have a different cause. I have had constant problems over the past number of years. And different solutions proposed by different plumbers. One - where the rads were cold on top and warm on bottom - I solved myself by unblocking the pipe from the attic tank with a piece of garden wire. The system wasn't filling. The current problem seems to be different. If it were the circulating pump wouldn't the problem arise with other rads as well? Do you think that the fact that the entry pipes and valves are hot has any significance?
 
With a problem like this you have to go back to basics, make sure your system water is nice and clean with a good bit of inhibitor in it,have your pump checked and replaced if need be, have your heating system balanced or fit trv s, which is a lazy mans way of balancing, as the valves close down as the rad get up to temperature pushing the heat to the colder rads , you could fit auto air releases at the systems highest point to help clear air from your system water, having a heating system that works shouldn't be unachievable, there are few things that can impact on the performance, but if you have a pump that works, clean system water and a balanced heating system with the right controls you will be taking a lot of issues out of the equation.
 
Thanks. These sound like sensible suggestions. Another point I should have mentioned. I have to vent two of the rads every ten days or so. Water in one of them is very black. These are on the ground floor of my two storey dormer. 15 rads in all. 10 downstairs, 5 upstairs. My system is an open one with a tank in the attic. There is no evidence of a leak, although since some of the pipes are buried in concrete it is possible that I have one. Would putting in an auto air release, as you suggest, on one of the upstairs rads be likely to help with the venting problem? Or do I need to go higher than this?
 
Fitting a auto air release in your case may mean you don't have to bleed the rad yourself, but if you have a system that needs bleeding every 10 days i think you should have your system checked for leaks and maybe system design also, as sometimes that can be a factor with drawing air into a heating system.
I would ask a plumber to have a look to identify the best position for your system.
 
My problem is that I have had several different plumbers look at the system but each one has a different diagnosis and prescription. One suggested that I re-pipe my entire system above the floors ie along the skirtings. He may be right but I have no way of knowing. I was not encouraged by the fact 1) that he did not look at the tank in the attic 2) he did not discover that the system was not filling and that there was a blockage from the tank. I rectified this myself and resolved at least one problem that I had for about three years - cool rads upstairs. Another has suggested that I move to a closed system. Another that I have the system flushed out. All of these may be necessary, but before I engage a heating engineer/plumber for another look I am trying to rectify as much as possible myself and find out as much as possible about the likely problems and solutions.
 
The first thing i would do is establish if there is a leak, if your system is leaking you will always have issues with contamination (sludge), if you can convert it to a pressurized system then i would, but be aware sometimes putting a higher pressure in to the rads can cause water leaks on older systems, but as yours is only 6 years old it is less likely to be an issue, once you have converted then you can monitor the pressure, which will let you know if you have a leak and how big, if you find there is no leak then you can flush(if you flush and there is still a leak you will lose or dilute any inhibitor you put in the water to protect the rads), if you find you have a leak then as your plumber said you can run your pipework surface, or you can try to isolate different sections of your heating circuit until you identify which part of the heating circuit is leaking, also a plumber may be able to pressure test your system, cutting off each section until he identifies which part of the circuit is leaking.
 
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