Firstly apologies for asking a question similar to that which many have asked before.
Trying to balance my system and achieve a reasonable delta T to get more condensing but just confusing myself at the moment despite lots of reading and research.
I have an Ideal Vogue system boiler in a conventional S plan with the central heating 2 way valve latched open.
The majority of the radiators (15 in total) are controlled via HR92s with the hall and landing still on traditional TRVs and the bathroom towel rad on two lockshields to act as a system by-pass when all the TRVs are closed. The rads are a mixture of sizes but are all of modern design.
The problem I have is that in order to get a reasonable temperature drop on most of my rads (approx. 10°C – not even trying for 20°C) the lockshields end up almost fully closed – they have a full range of approx. 1and ¾ turns and most end up say 1/16 to 1/8th open.
This would be fine but I then end up with quite a lot of radiator noise, especially as the house warms up and TRVs/HR92s start closing. The boiler has a modulating pump so I thought it might compensate as the TRVs close and therefore prevent the noise but it seems to run at 100% when it gets to this stage, not sure why, maybe needs the extra pressure in order to achieve a minimum flow rate via the open rads as the other TRVs close.
It occurred to me that if I just open up all the lockshields to say 1 turn open then maybe the pump would modulate and lower the pressure whilst achieving the same flow rate.
This has made the system virtually silent and I’ve had no problems with rads being starved of heat (the system is made up of 28, 22 and 15mm pipe as things gradually tee off so probably provides a reasonable inherent balance regardless of lockshield settings).
The pump however still seems to spend most of the time running at 100% and I’m not getting good temperature drops across most of the radiators. I thought the pump might adjust to try and achieve a reasonable delta T and therefore opening up the lockshields would allow the pump to run at say 60% instead of 100% most of the time.
The pump is largely automatic, I can change it from min to max modulation in the settings but this doesn’t seem to make any difference.
I therefore seem to be in a catch 22 situation – either retain a reasonable delta T (and more condensing) at the expense of having system noise (and I suppose extra power used by pump) or vice versa.
Is there something I’m missing here? Maybe I need a 'proper' ABV rather than using the towel rad (along with the boiler inbuilt ABV) but I really don't fancy draining the system down and breaking into the pipework to do this.
Any tips would be appreciated.
Trying to balance my system and achieve a reasonable delta T to get more condensing but just confusing myself at the moment despite lots of reading and research.
I have an Ideal Vogue system boiler in a conventional S plan with the central heating 2 way valve latched open.
The majority of the radiators (15 in total) are controlled via HR92s with the hall and landing still on traditional TRVs and the bathroom towel rad on two lockshields to act as a system by-pass when all the TRVs are closed. The rads are a mixture of sizes but are all of modern design.
The problem I have is that in order to get a reasonable temperature drop on most of my rads (approx. 10°C – not even trying for 20°C) the lockshields end up almost fully closed – they have a full range of approx. 1and ¾ turns and most end up say 1/16 to 1/8th open.
This would be fine but I then end up with quite a lot of radiator noise, especially as the house warms up and TRVs/HR92s start closing. The boiler has a modulating pump so I thought it might compensate as the TRVs close and therefore prevent the noise but it seems to run at 100% when it gets to this stage, not sure why, maybe needs the extra pressure in order to achieve a minimum flow rate via the open rads as the other TRVs close.
It occurred to me that if I just open up all the lockshields to say 1 turn open then maybe the pump would modulate and lower the pressure whilst achieving the same flow rate.
This has made the system virtually silent and I’ve had no problems with rads being starved of heat (the system is made up of 28, 22 and 15mm pipe as things gradually tee off so probably provides a reasonable inherent balance regardless of lockshield settings).
The pump however still seems to spend most of the time running at 100% and I’m not getting good temperature drops across most of the radiators. I thought the pump might adjust to try and achieve a reasonable delta T and therefore opening up the lockshields would allow the pump to run at say 60% instead of 100% most of the time.
The pump is largely automatic, I can change it from min to max modulation in the settings but this doesn’t seem to make any difference.
I therefore seem to be in a catch 22 situation – either retain a reasonable delta T (and more condensing) at the expense of having system noise (and I suppose extra power used by pump) or vice versa.
Is there something I’m missing here? Maybe I need a 'proper' ABV rather than using the towel rad (along with the boiler inbuilt ABV) but I really don't fancy draining the system down and breaking into the pipework to do this.
Any tips would be appreciated.
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