Just moved into a new house and have a problem with two radiators which are only getting luke warm and no where near as hot as the others and really struggling to heat the rooms they are in. I've been under the floor which is quite easy to move around in for the most part and have traced as much of the pipework as I can.
(I have not yet seen the pipework to rads 11, 12 and 13 as I cannot get under that floor right now - what I can say is that with those rads off, the flow and return pipes still get hot at points A and B - could there be some sort of bypass - they wouldn't just connect flow and return directly with 22mm would they?). There is an upstairs which is working well and tees off near the boiler - I haven't mapped that out yet and am not concerned about it, closing down the upstairs doesn't seem to have any effect on my problem rads.
Pipework is 22mm for the main flow and return legs as far as I can see, and branches off in 15mm all the way to the rads. What surprised me is the mix of rads that are connected to flow and return (just rads 4 and 8 ) and rads that are connected in parallel with main flow or return pipes(I haven't come across this way of connecting them before). Most rads seem to get hot enough, especially 4 and 8 which get mad hot until I closed them down a bit.
The problematic ones (unsurprisingly looking at this plan!) are 1 (towel rail in en-suite) and 2 (bedroom rad) - cannot see the exact piping between these rads so assuming a little bit they are like this - I can only see where they tee off the 22mm flow. These two are maybe 4-5m of 15mm pipework away from the 22mm, and the tees on the 22mm are less than half a metre apart - was this ever going to work properly? (surely there isn't enough pressure difference to give a good flow?) The flow is just too low - even with the valves fully open the return pipe of the radiator barely gets warm, the towel rail manages a bit better as its smaller and maybe more free flowing, but still not great.
So in my mind, the solution is just to repipe one of the legs from the flow over to the return? I'd probably get a man in to do this and its a full drain of the system. Is this the best option?
In the mean time, is there a configuration of the rest of the rads that could improve the flow through the problematic section? I initially closed down a lot of the lockshields to try and push more water into these rads (expecting everything to be flow/return), but now I've mapped it out I guess this was the wrong thing to do. It looks like the rads in parallel with the flow/return will have very little effect on the flow through other radiators? Whereas opening up rads 4 and 8 should increase the overall flow which might allow more to flow through 1 and 2??
(I have not yet seen the pipework to rads 11, 12 and 13 as I cannot get under that floor right now - what I can say is that with those rads off, the flow and return pipes still get hot at points A and B - could there be some sort of bypass - they wouldn't just connect flow and return directly with 22mm would they?). There is an upstairs which is working well and tees off near the boiler - I haven't mapped that out yet and am not concerned about it, closing down the upstairs doesn't seem to have any effect on my problem rads.
Pipework is 22mm for the main flow and return legs as far as I can see, and branches off in 15mm all the way to the rads. What surprised me is the mix of rads that are connected to flow and return (just rads 4 and 8 ) and rads that are connected in parallel with main flow or return pipes(I haven't come across this way of connecting them before). Most rads seem to get hot enough, especially 4 and 8 which get mad hot until I closed them down a bit.
The problematic ones (unsurprisingly looking at this plan!) are 1 (towel rail in en-suite) and 2 (bedroom rad) - cannot see the exact piping between these rads so assuming a little bit they are like this - I can only see where they tee off the 22mm flow. These two are maybe 4-5m of 15mm pipework away from the 22mm, and the tees on the 22mm are less than half a metre apart - was this ever going to work properly? (surely there isn't enough pressure difference to give a good flow?) The flow is just too low - even with the valves fully open the return pipe of the radiator barely gets warm, the towel rail manages a bit better as its smaller and maybe more free flowing, but still not great.
So in my mind, the solution is just to repipe one of the legs from the flow over to the return? I'd probably get a man in to do this and its a full drain of the system. Is this the best option?
In the mean time, is there a configuration of the rest of the rads that could improve the flow through the problematic section? I initially closed down a lot of the lockshields to try and push more water into these rads (expecting everything to be flow/return), but now I've mapped it out I guess this was the wrong thing to do. It looks like the rads in parallel with the flow/return will have very little effect on the flow through other radiators? Whereas opening up rads 4 and 8 should increase the overall flow which might allow more to flow through 1 and 2??