How quickly does LLH create heat

[Zencap]

When you have only the rads on any other pipes get hot except the mains into the llh ?

Hi Shaun, no they don’t, only just to the pumps (for UFH and HW) but obvs pumps not on so stops there. Tiny distance.

 

[Zencap]

You shouldn't require running the circ pumps at full speed especially with the UPS3 as it gives a head of 6.4M under all your flow requirements, it will result in a higher boiler return temp which impacts on efficiency, also higher pump electrical consumption.
I would buy a heat gun or even more accurate, a clamp on thermocouple thermometer to take the boiler and the individual circuit flow&return temps, you can then easily see the lowest head required for your system and also the performance of each circuit plus the lowest boiler return temperature.

Ok so think reduce the pump power for CH and UFH down one level? Or maybe just the UFH?

Also do you think the flow from boiler (and return) changed to 28” vs 22” would mean greater flow to LLH thus more “hot” water to be pumped round?

 

[ShaunCorbs]

Hi Shaun, no they don’t, only just to the pumps (for UFH and HW) but obvs pumps not on so stops there. Tiny distance.

None of them return heat up do they ?

 

[John.g]

Ok so think reduce the pump power for CH and UFH down one level? Or maybe just the UFH?

Also do you think the flow from boiler (and return) changed to 28” vs 22” would mean greater flow to LLH thus more “hot” water to be pumped round?

I would suggest changing the boiler, CH & UFH circ pumps to speed 2 (5.2M), you should then ensure the UFH loop flowrates are as before.
You really require a few temperature sensors to get the proper picture, you might purchase say 6 or so spring clip on dial thermometers and you can monitor all the flows and returns together or one of the two types mentioned above.

What do you mean by 28" vs 22"?.

 

[Zencap]

None of them return heat up do they ?

Not sure what you mean, you mean on the returns? No if so. If Ch on only pipes that get warm/ hot are the CH.

 

[Zencap]

I would suggest changing the boiler, CH & UFH circ pumps to speed 2 (5.2M), you should then ensure the UFH loop flowrates are as before.
You really require a few temperature sensors to get the proper picture, you might purchase say 6 or so spring clip on dial thermometers and you can monitor all the flows and returns together or one of the two types mentioned above.

What do you mean by 28" vs 22"?.

Wil invesitagte temp sensorrs

I mean the size of pipe to and from the boiler - it is only 22 inch, should it be 28” copper pipe and thus allow great flow to the LLH?

 

[John.g]

22" should be fine, bags of pump power available.