How to get underfloor heating flowing

[John.g]

You might also post the number of zones & loops, the flowrates from the individual flow meters and the manilo;d flow & return temperatures.

 

[Mwhp1986]

Well a flow issue is a flow issue irrelevant of how many loops however there are 7 loops for 4 zones with flow rates of 1, 1.2, 1, 0.5 l/m for each zone respectively. As previously stated in earlier in the feed it’s 44deg

 

[Mwhp1986]

With anywhere from 18.5 - 22 difference

 

[John.g]

Well a flow issue is a flow issue irrelevant of how many loops however there are 7 loops for 4 zones with flow rates of 1, 1.2, 1, 0.5 l/m for each zone respectively. As previously stated in earlier in the feed it’s 44deg

Those flow ratate are far too low which is what you mean??, and thats why the returns are so low, they should, IMO, be in the range of 2.0/2.5 LPM, 7 loops at 2.5 LPM = 17.5 LPM manifold flow rate. if the flow/return was say 44/38C then the boler demand will be 9.8kw with a circ flowrate 6.1 LPM with a flow/retur temp of 60/37C, dT of 23C. (assuming boiler SP temp at 60C), The boiler might be happy operating like this?

 

[John.g]

Or if 3.7LPM/zone = 14.8LPM