Hot water drops off and radiator not heating fully
Anonymous user 23/02/2024 - 3.01 PM
I've been bleeding all the radiators and on the ground floor and all but 1 seem to heat up fully (bleed valve is fairly tightly shut on the one double rad not heating fully). Upstairs the rad are partially heating up about 1/2 way and have been trying to bleed them gradually to bring them up. Have also noticed the hot water seems to drop off after a while and the valve going to the tank in the airing cupboard in the bathroom needs bled to get the pipes heating up going to it (this sometimes has no effect). The rad at the top in the roofspace is not heating up at all. Any ideas as to why this might be? I can't hear any tanks filling with water when bleeding the rads either.
Are you a tradesperson and able to answer this question?
Please tread very carefully before committing to Power-flushing alone. It seems to me that the problem is with a "Blocked Cold feed" pipe. Any competent heating engineer would know exactly where to look as this is quite a common problem.
As the blockage usually occurs from the point of connection of the cold feed and may extend a few inches up the pipe, Power Flushing will not resolve as the blockage is on a part of the system with no circulation.
Best to drain the system and cut out the small section of blocked pipework.
Power-flush by all means if the system is highly contaminated but this alone will not clear a blocked cold feed.
Hi resolved, from your description it would seem that your heating system is suffering from a build up of "Sludge" caused by corrosion inside the heating pipework. What you are bleeding out of the radiators is not air but Hydrogen which is a by product of the sludge. This sludge not only creates cold spots on radiators and the need for constant bleeding of the system but will also block up the waterways inside the boiler and the pump reducing the efficiency of the system. A simple test is to bleed the radiators and note the colour of the water. if it is very dark brown or black then i would suggest that this is your problem. If this is the case then the heating will need to be Powerflushed and treated with chemical cleansers such as Fernox. Any proficient plumber will offer this service.
