Hi there, I recently drained my heating system using a drain cock on a downstairs radiator so that I could clean out the small top up tank in the loft. I cleaned the tank(there was a good inch or two of sludge in there) and put some central heating cleaner in and then let the tank fill itself again. Then a few hours later I turned the heating back on to find that only 1 radiator would get warm. I thought there might be an air lock because the radiator I used to drain the system had a broken TRV and drain cock so I replaced all that with a new drain cock and manual valves on both ends, I then took the radiator off and flushed it outside using the garden hose. Before putting it back on the wall I (whilst the heating was on max) tried to get the water flowing through the system by opening the valves with the rad disconnected. All I get is some residual water trickling out and then nothing. There seems to be no 'flow' around the system at all. The boiler does fire up and makes all the right noises but all it does is heat up the radiator that is just across the room. I thought there may be a blockage in that radiator so I had that off and flushed that too but still no change to the rest of the system. I'm not really sure what to try next, any help would be appreciated. Lee
As long as the motorised valve is working properly, I think you may have a blockage caused by the sludge going down the cold feed pipe from the tank. You can try turning off any rads that work at one end and see if the water then goes to next rad. If it doesn't it is probably a sludge blockage or an air lock in the pipe. Try putting a hose pipe on the rad downstairs on the valve with one end of rad disconnected. turn tap on, open valve and see if you can push the water up into the tank, get someone to look for you so you can turn water off quickly. If it works repeat for other rad valve on same rad. And did you get your soil pipe turned in the end?
Hi, the feed from the tank should of been high enough to stop any sludge going down the pipe, unless it was disturbed, check the pump is running, then unscrew the vent plug on the pump spindle (big flat screw driver rqd) with a tray below to catch water, you can do this with pump running, you should see spindle spinning also this releases air,replace screw, also check for AAV that releases air has its vent screw loose. Failing that,i turn of main to tank, drain the system again bleeding every rad upstairs, then go up to f&e tank in roof & blow down the vent pipe, if this is blocked or a plug of water is sat there the system can't vent air when your trying to re fill it, then fill system again & vent all radiators, then raise the water level in tank above normal level by holding down float, this will increase head hopefully pushing air lock out,
Thanks for the advice guys, lots of things I can try there. I haven't rotated my stack yet Peter as I'm still waiting for the new toilet to be delivered, hopefully next weekend it should be ready to rotate. I forgot to mention that the top up tank did overflow initially when upon refilling, which is a bit of an issue in this house as the overflow runs straight onto an aging flat roof of the building on the side of my house. I had to get a couple of litres out of the tank with a cup and bowl to stop it pooling on the roof. I'll have another look at this tomorrow but the whole system is not in a serviceable condition in my opinion, every drain cock needs replacing and almost all radiators have ancient TRVs that leak through the fittings. I think I'll be off to the plumbers merchants tomorrow, thank god the weather is warm. I'll let you know how I get on. Thanks again.
Update on this - http://s1263.photobucket.com/user/leeevernden1/media/photo16_zpseb97f0b8.jpg.html][/URL] I attatched a hosepipe to a return radiator valve and I did get some very encouraging results from that. After some spluttering water flowed into the top up tank via the pipe on the left, bringing some sludge with it mind. Unfortunately this filled my tank and I then had to empty it by hand as it does not drain anymore - This is quite time consuming and I couldn't finish this before Mrs x300 got home and ordered me to stop what I was doing and look after our 2 year old as Neighbours was on TV! She then moaned that it was cold later that evening . Anyway I have a feeling all I have to do now is do the same on the other valve as suggested already and it should blow the blockage back into the tank, I'll let you know how I get on. Thanks again for your help.
OK this is still unresolved!!! The missus is close to calling in a plumber now. Here is what I have done since the last update: So as I thought I'd blocked my heating system up with tank sludge I attached the garden hose to a downstairs radiator feed valve, then I capped off the return pipe in the loft and manually emptied the top up tank as it could no longer drain from a drain cock downstairs. Then I turned on the outside tap and let the pressure build, sure enough the blockage was blown out and the topup tank filled up from the feed pipe. Then I turned off the outside tap and opened up a downstairs draincock and the tank drained fully. Hooray I thought, so I popped my inhibitor in the tank and filled it back up after closing the drain cock. Then I whacked the heating and hot water on and turned the thermostat up full. Unfortunately though not much has happened, I still get one radiator downstairs gets warm - The feed side is hot but the return side isn't. And then a couple of radiators upstairs get luke warm when the return pipes heat up but nothing else. Then after a while everything gets stone cold again. Time is a factor now as my immersion has packed up despite the element being 6 months old and the fuse is ok Any help with the heating issue would be greatly appreciated as I can't afford a plumber!!!
Also forgot to mention I took a radiator off downstairs and opened the valves fully in turn to see whats going on. The feed side had good flow straight away but was stone cold, after 5 litres or so I gave up hoping for hot. Then I opened the return side and it coughed and spluttered out grey/black stuff, then the flow was good and it got hot. This seemed to heat up the return valves on a few rads around the house but the soon went cold again.
I dont know if you have cleared it all yet but this system sound as though it is a good candidate for a powerflush. But seeing as though there is a financial factor you could try adding a system cleanser, go for the stronger one, something like Sentinal X800 or Fernox F5. Add to the system leave in for about a week, running the heating as much as is practical, occasionanly going around and bang the raditors to shift any debris. Then thoroughly drain the system, wouldnt hurt to remove each Radiator and flush it out outside. When you have finished add an inhibitor to the system Fernox F1 or Sentinal X100. You could also look at fitting an inline magnetic cleaner I.E. a Magnaclean of Fernox TF1. Dave
I was hoping more flushing wouldn't be the answer! Also the pump can be heard making what sounds like a very loud cat purring, I certainly do not remember it ever making that noise. Does it need bleeding or is it buggered or just over worked?
That sounds like lack of water in the pump, you may well have a blocked cold feed, the best remedy is to cut it out and replace it.
Hi there, This issue is now resolved. I had indeed cleared the blockage with the last garden hose trick from a previous post. However the reason that nothing was working was due to the fact that my system does not have an AAV fitted, therefore as stated previously the system was unable to vent when re-filling and there was too much air in the pump causing the noise. I was looking for the AAV to check the screw was loose but was shocked to find in its place a radiator valve. I opened the valve and that released the air in the system and all was well. So thanks for your help, you were all right in the end. I may now have to fit an AAV but I think I'll give it a rest for a while.
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