Hi I recently replaced some of my radiators because the bottoms of them were not warming even though we had got someone to do a power flush on them. after replacing them with some brand new ones we are still getting the same problem. We have bled them to see if there is an air block but there isn't. I don't know what to do now and I woukd like as much help as possible. Its a large house and I don't fancy another winter in the cold. Thanks.
What type of system do you have is it a sealed system, Y plan, S plan two pipe, one pipe, Gravity. Bit more information and maybe we can work out an answer for you. Is you pump running at the correct speed? can you run the central heating without the water? if so do that then shut down the rads that are working that should force the heat around then open up the closed ones. Your system may just need to be balancing.
T To be honest with you I dont know. All I know is that I have a baxi 105 he boiler and a mixture of copper and plastic pipes at 15mm. Hope this helps.
Turn off all rads except for one 'problem' rad. Does it get hot? Repeat for all 'problem' rads. If the rads heat up when they are on by themselves, the system needs balancing.
Ok thats a combination boiler and its a sealed system. First thing you may want to look at is the system pressure pull down the flap and on the right is a pressure gauge it should be between 1 and 1.5 bar with the system cold. If its low top it up. On those boilers as I remember there could be an integral filling loop or you may have a remote one. One other thought are you getting any heat from all the Rads or just some and not others. You say yours is a big house how many radiators are we talking about and has there always been this problem.
The pressure gauge is on 2. The problem that I had before is the same as now. Some of the rads do warm up. There is a thing that you turn and it tops up. We have 11 rads in total. Thanks
Great news! Turned off all rads except 1 of the bad ones and it heated up from top to bottom. Did the same with the rest also and they worked fine individually, I also bled each rad whilst doing this. I gave each rad a bit of timeto get hot then I turned it off and then moved inonto the next one. once I copleted this I turned all the radiators on and was faced with the same problem again, hot at the top and warm at the bottom. I also noticed that some of the rads had the new trv's that I bought on the outlet side and some on the inlet side, does this make a difference? Cheers again.
As long as the TRV's are reverse flow it won't make a massive difference, any professional installing them will always try to get them on the flow as they do work better. Sounds like all you need to do is balance the system. Providing the pie sizing for the system is correct the boiler has something like 30Kw output which is plenty for an 11 rad system. Being as this is a long term problem I would defiantly look at the system pipe sizing and layout.
I have just started balancing the radiators andnoticed water dripping from the flue. Is this common or is there a pproblem?
Its an HE boiler so it produces condensate, the flue however should be angled slightly back towards the boiler so that the condensate runs back into the boiler
Good news I have managed to balance them. I couldnt work out the circuit or layout of the system so I just closed the rad that is most closest to the boiler more than the the rest of the rads. The rest I had to basically adjust based on the temperature of the pipe and rad. Anymore input will be appreciated. Thanks
Sounds like a good first attempt. If you still have problems, here are detailed balancing instructions. 1. Remove all TRV heads and set all wheel valves to fully open. 2. Set all lockshield valves to 1/3 of a turn open from closed (fully clockwise). 3. Start boiler and allow system to warm up 4. Feel all return pipes (cooler one) to see how warm they are. 5. Select one which is midway between the hottest and coldest and use it as a 'standard'. 6. Any rad with a hotter return than the 'standard' should have the LS valve closed a tiny fraction. 7. Any rad with a cooler return should be open a tiny fraction. 8. Repeat 4 to 7 until all returns are approximately the same temperature. Do no expect perfection. The adjustment each time is very small and you need to leave time (say 10 mins) between each cycle for the system to settle down. When finished replace all TRV heads and set to required temperature. Set all wheel valves to required position.
Thanks for your advice. Does the above info include the problem rads also? Or just the rads that were working fine previously?
Was wondering how I balance radiators that dont have trv's on them ie in bathroom. Also one of my rad is in opposite side to all the others, I believe that it doesnt run on the other radiators circuit, do I need to balance this also?
look at the setting on the pump, then balance the lock shield valves by turning them down and slowly turning them up so they get warm. Sounds like you have gravity hot water and pumped heating, worse case scenario you have a one pipe system and someone has fitted a new boiler to it. This won't work properly I'm a afraid and you will need an entire repipe which will cost you a few thousand to fix. Too many people are being ripped off by the powerflush scam, they are very rarely needed and I only ever use them when I'm fitting a new boiler and this is purely for the warranty. Sludge in radiators tends to collect in the bottom of radiators and in some cases will block pipe completely....adding aggressive chemicals and pumping them round an old system is asking for trouble. I've seen many a radiator balloon thanks to a powerflush. I use the magna clean fast cleanse on new systems which protects the boiler from unwanted junk. In the event of poor performing raditors or blocked pipe then it simply comes down to good old fashioned plumbing (new pipe and new radiator). Only the other month a got a previous British Gas customer who had been charged over £400.00 for a powerflush for a house will just 6 radiators......they then fitted a magna clean for £250.00 and a new plate heat exhanger for £375.00.....tot all this up and you are getting very close to a new boiler anyway...
How do I check what the setting on the pump is and how do I adjust the valves accordingly? The central heating seems to work fine now since I've balanced the rads. I bought the house from someone that I know. He put a brand new system in including rads, pipes and boiler. The only problem that I found with this system was that the rads were not giving enough output for the size of the rooms (huge rooms, small rads). Therefore I changed some of the rads and I still had the balancing problem from previous because even with the old radiators there was a balancing problem. Do I still need to change the pipes in your opinion?
It's all in the instructions. Set the wheel valve to max and balance using the lockshield valve. What to you mean by "in opposite side"?
I mean its on the other side of the house not following the circuit with the majority of the rads. The pipes for this rad dont have any 't'ing off it. Hope this makes sense.
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