So, I have a gas system boiler(Trianco Optima 28SB) that's in a y-plan set up but rather than heating a cylinder for hot water, it goes through an external plate heat exchanger to act like a combi.
Now when the heating is on, and then HW is demanded, HW comes out hot quite quickly.
When heating is off and hence boiler is cold, hot water can take a minute or more before it's at an acceptable temperature. This is because the boiler takes this long to reach a decent flow temperature.
The observations are the heating flow runs at about 70 degrees with a return temp around 55 and gets up to this quite quickly.
With boiler cold and HW only demanded, the temp climbs slowly to about 60 degs.
My question is does the return temperature control the flow temperature. This would explain it as most of the return heat is being sucked out by the efficient PHE.
My thinking is to perhaps put a mixer valve in after the PHE to raise return temp.
So am I correct in the return temp governing the flow?
And would the mixing valve idea work (or maybe just a bypass valve)?
Now when the heating is on, and then HW is demanded, HW comes out hot quite quickly.
When heating is off and hence boiler is cold, hot water can take a minute or more before it's at an acceptable temperature. This is because the boiler takes this long to reach a decent flow temperature.
The observations are the heating flow runs at about 70 degrees with a return temp around 55 and gets up to this quite quickly.
With boiler cold and HW only demanded, the temp climbs slowly to about 60 degs.
My question is does the return temperature control the flow temperature. This would explain it as most of the return heat is being sucked out by the efficient PHE.
My thinking is to perhaps put a mixer valve in after the PHE to raise return temp.
So am I correct in the return temp governing the flow?
And would the mixing valve idea work (or maybe just a bypass valve)?
