DIY Doctor UK DIY Forums

Hello,
I have an issue with the last radiator to heat up on our system. It takes an age to heat up and never gets as hot as the others. I have balanced the system several times with no success and had the system cleaned. I think part of the issue is the second to last radiator. If you shut off the second to last radiator it shuts of the water to the last radiator. It’s as if there is no bypass and the water has to pass through the second to last radiator to reach the final radiator. Would the solution be to put a bypass pipe that connects the inlet / outlet of the second to last radiator. This would mean I can turn down the valve on the radiator and force more water the the final problem radiator. Or is it not as simple as that?
Thank you for any advice.

I am not a plumber, but it seems odd that two radiators are piped in series rather than parallel. I remember the old school central heating, a pipe ran all the way around the school, and there was a restriction in pipe diameter under each radiator to force the hot water through the radiator, and the radiators got bigger and bigger as the water would get cooler and cooler, but not seen that system in a house.

There was a problem with fan assisted radiators as unlike free standing they don't have a lock shield valve to restrict the flow, as to if they could be piped in series I don't know?

It does seem some one has made a mistake with the piping, however I would want to see it myself before saying there was an error.

I struggle to believe someone would have installed it like that myself. The radiator (second to last) is in the extension which was constructed before we bought the house.

I can’t think of a simple way to check other than to rip the floor up and chase the pipework?

I would consider a by-pass rather than re-pipe, however it would need to be for both radiators, I would consider piping up a radiator that way when both in the same room, and first radiator was a myson fan assisted which does not have any restriction on water flow, it simply switches the fan on/off so it can return hot water back to the boiler and so cause boiler to modulate, the second radiator having a TRV will restrict flow once room is warm enough.

So it could be originally a fan assisted but changed before they left, however think a lock shield valve across radiator, rather than by pass valve would be needed, as likely not enough pressure to lift the by pass.

I also found some odd central heating when I moved into this house, to turn on boiler there was a time switch, no thermostat in main house, in the flat below the main house a thermostat turned on a pump, but for main house to run central heating one had to leave house walk around to flat which was a garage and plug in the pump, it simply had a 13A plug on the pump, not thermostat or any other control.

Also three separate FCU's feeding the boiler, from two separate consumer unit/fuse box.

I just wonder how they lived with that system?