2nd That 🙂 I'll be honest, the last relay I worked with was replacing the one inside an old Potterton. Other than that I know 'nowt' about them Other than a voltage switch eg 230v to 24v Keen to learn from scratch
If the Close coupled tees are physically close then the differential pressure the UFH pump applies to the main circuit is small. The valve is a neat idea but when it is closed ( & the Tees are uncoupled) what stops the cooled UFH pump returning water going thro the radiators? ..could we perhaps put a one way valve in between the CCTs ? It would have to be big bore not to create a differential pressure on the boiler circuit, when the UFH flows across it, But that would ensure no boiler water flowed through the "short circuit" when the UFH wasn't taking enough boiler water.
In series with the zone valve, do you mean (on the return or the flow: it makes no difference). If the balancing valve supplies precisely the flow required for the kW rating of the UFH, I'm inclined to agree with you - you set the valve once the UFH is up to temperature and with the radiators running and you balance as if the UFH manifold were a radiator. Though the fact that you will inevitably provide _just a little_ more rather than less primary flow than the UFH needs means you will be increasing the primary return temperature which, desirable on an old boiler, is not desirable with a condensing boiler. I can see, however, that if the UFH requires more flow than the boiler can provide, this solution is only going to work if the UFH runs at a lower temperature than the boiler is providing. In which case the UFH blending valve can, once up to heat, mix boiler flow water with UFH return water and thus have a greater flow than through the boiler itself. Am I making sense of this?
Hi andrew Pls a quick(naive question) in the top diagram the closed coupled tee there is an external pump (also one in the boiler) the question if i have only system boiler can i put a closed coupled tee? Also if u have a heat only boiler with external pump can i have a cct or that mean i would need an extra small pump just before the return to the boiler. Much appreciated
@@andrewmillwardwatford9410 short answer yes very much helpful. Way i understand it: any where CCT, LLH & Plate Hex used then the branched circuits need their own pumps? In case of Heat only boiler then the primary return to boiler would need its own pump also. Right?
Hi Andrew, is there any advantage or disadvantage of forming the CCT in 35mm, followed by 35mm upstream and downstream of CCT, down to 22mm to go through the filter and air separator and connect to boiler? Or just run the whole loop in 22mm?
@@aliatas6647 sorry I just reply to you thinking I was replying on a Facebook post. Yes there are rules for distances from elbows I think if you Google close coupled Tees you'll find the images you may have to Google closely space Tees
@@andrewmillwardwatford9410 thanks Andrew. Can you feed multiple secondaries of the single CCT from the primary loop? Or do you need to have multiple CCTs feeding each zone separately? I only ask after googling this stuff and would be great to know you're experience of it.
@@aliatas6647 I'm afraid none of your questions have very straightforward simple answers. You can have both but having multiple close couple teas suitable for use with weather compensation so it's not something that I would recommend other than if you're trying to fix an old system has no real weather compensation option
Well explained - as always.👍
You will have to do a relay morning Andrew, or take time to show me . Keen as this is a decent inexpensive fix. Good thoughts.
I'd be happy to do a relay event.
2nd That 🙂
I'll be honest, the last relay I worked with was replacing the one inside an old Potterton. Other than that I know 'nowt' about them
Other than a voltage switch eg 230v to 24v
Keen to learn from scratch
If the Close coupled tees are physically close then the differential pressure the UFH pump applies to the main circuit is small. The valve is a neat idea but when it is closed ( & the Tees are uncoupled) what stops the cooled UFH pump returning water going thro the radiators? ..could we perhaps put a one way valve in between the CCTs ? It would have to be big bore not to create a differential pressure on the boiler circuit, when the UFH flows across it, But that would ensure no boiler water flowed through the "short circuit" when the UFH wasn't taking enough boiler water.
How about balancing valve before ccts? wouldn't thats be easier? Also don't manifold have their own bypasses so they an achieve higher flow rate?
In series with the zone valve, do you mean (on the return or the flow: it makes no difference). If the balancing valve supplies precisely the flow required for the kW rating of the UFH, I'm inclined to agree with you - you set the valve once the UFH is up to temperature and with the radiators running and you balance as if the UFH manifold were a radiator. Though the fact that you will inevitably provide _just a little_ more rather than less primary flow than the UFH needs means you will be increasing the primary return temperature which, desirable on an old boiler, is not desirable with a condensing boiler.
I can see, however, that if the UFH requires more flow than the boiler can provide, this solution is only going to work if the UFH runs at a lower temperature than the boiler is providing. In which case the UFH blending valve can, once up to heat, mix boiler flow water with UFH return water and thus have a greater flow than through the boiler itself.
Am I making sense of this?
Hi andrew
Pls a quick(naive question) in the top diagram the closed coupled tee there is an external pump (also one in the boiler) the question if i have only system boiler can i put a closed coupled tee? Also if u have a heat only boiler with external pump can i have a cct or that mean i would need an extra small pump just before the return to the boiler.
Much appreciated
All hydraulically seperated circuits need their own pump. Does that help ?
@@andrewmillwardwatford9410 short answer yes very much helpful.
Way i understand it: any where CCT, LLH & Plate Hex used then the branched circuits need their own pumps?
In case of Heat only boiler then the primary return to boiler would need its own pump also.
Right?
@@conand1413 correct
Hi Andrew, is there any advantage or disadvantage of forming the CCT in 35mm, followed by 35mm upstream and downstream of CCT, down to 22mm to go through the filter and air separator and connect to boiler? Or just run the whole loop in 22mm?
No need to up size
@@andrewmillwardwatford9410 Thanks Andrew. Are there any rules to follow regarding distances to elbows etc?
@@aliatas6647 sorry I just reply to you thinking I was replying on a Facebook post. Yes there are rules for distances from elbows I think if you Google close coupled Tees you'll find the images you may have to Google closely space Tees
@@andrewmillwardwatford9410 thanks Andrew. Can you feed multiple secondaries of the single CCT from the primary loop? Or do you need to have multiple CCTs feeding each zone separately? I only ask after googling this stuff and would be great to know you're experience of it.
@@aliatas6647 I'm afraid none of your questions have very straightforward simple answers. You can have both but having multiple close couple teas suitable for use with weather compensation so it's not something that I would recommend other than if you're trying to fix an old system has no real weather compensation option