Recently bought a house - to be honest, I had a fair idea what I was getting as I already have a flat next door in the same development. Since it was built, British Gas have been in and done a nice untidy boiler replacement
Anyway, my expectations were to find all the lockshields fully open, and I wasn't disappointed when I had a go at balancing the system tonight.
So, what does the advice say about balancing ? Well one step is turning down the pump to set the flow in the "slowest" rad in the system. But this is a crappy combi - so you can't do that without affecting the DHW as well.
So off round the system I go, shutting down the lockshields to try and get some semblance of system balance. I'm still in single figures when the valves are getting noisy. I give up aiming for 12˚C temperature difference and go for 10˚, then 8˚, then 6˚, and finally settle at just 5˚ at which point the bathroom and back bedroom are about at a tolerable noise level (bathroom is only 4˚.
But here's the special features of this system. It's 22mm from the boiler up into the upstairs floor, and it arrives at the rads as 10mm. Clearly the small front room upstairs is fed from two pipes which are touching and not lagged - the flow temp is a full 15˚ less than some other rads ! The living room downstairs has pipes dropped from upstairs - buried direct in the plaster down the wall. Lockshield fully open and it's still giving 9˚ drop, while the back bedroom is barely acceptable for noise at only 5˚. And the surface of the plaster is above 50˚ where the pipes are buried.
Just for good measure, there are two small rads in the dining area fed by their own 10mm branch tapped off close to the boiler. In this case, a full 20+˚ lower flow temperature than the other rads (and only 3˚ drop) - yup unlagged pipes run touching each other
Needless to say, except when the wether is mild and the boiler flow temp can be turned down, it's not going to be condensing very much.
I guess I'll just have to save up and get a thermal store fitted like I've done in the flat - fully TRV'd system (fully modulating pump), and above all no combi Needless to say, the house if built to maximise difficulty of altering anything like this
Anyway, my expectations were to find all the lockshields fully open, and I wasn't disappointed when I had a go at balancing the system tonight.
So, what does the advice say about balancing ? Well one step is turning down the pump to set the flow in the "slowest" rad in the system. But this is a crappy combi - so you can't do that without affecting the DHW as well.
So off round the system I go, shutting down the lockshields to try and get some semblance of system balance. I'm still in single figures when the valves are getting noisy. I give up aiming for 12˚C temperature difference and go for 10˚, then 8˚, then 6˚, and finally settle at just 5˚ at which point the bathroom and back bedroom are about at a tolerable noise level (bathroom is only 4˚.
But here's the special features of this system. It's 22mm from the boiler up into the upstairs floor, and it arrives at the rads as 10mm. Clearly the small front room upstairs is fed from two pipes which are touching and not lagged - the flow temp is a full 15˚ less than some other rads ! The living room downstairs has pipes dropped from upstairs - buried direct in the plaster down the wall. Lockshield fully open and it's still giving 9˚ drop, while the back bedroom is barely acceptable for noise at only 5˚. And the surface of the plaster is above 50˚ where the pipes are buried.
Just for good measure, there are two small rads in the dining area fed by their own 10mm branch tapped off close to the boiler. In this case, a full 20+˚ lower flow temperature than the other rads (and only 3˚ drop) - yup unlagged pipes run touching each other
Needless to say, except when the wether is mild and the boiler flow temp can be turned down, it's not going to be condensing very much.
I guess I'll just have to save up and get a thermal store fitted like I've done in the flat - fully TRV'd system (fully modulating pump), and above all no combi Needless to say, the house if built to maximise difficulty of altering anything like this