- Messages
- 17
Good evening Gentlemen (and ladies?).
I have a large holiday let, in rural Somerset, and commercial heating engineers are rare out here. I’m a design engineer by education, so have taken on the task of getting this system running better than it is at the moment.
Long story short, the heat isn’t going where I expect and want it to go.
System comprises of a Grant oil boiler - 58/70 feeding a LLH six feet away. The primary is pumped with a digital variable speed DAB pump. The secondaries are pumped / zoned with similar DAB pumps.
Surely, when the heat load is large, eg on startup, the LLH should almost ‘not be there’ from a heat point of view? IE the hot from the boiler flow (at 74C) should pretty much be the flow to the rads? Plus or minus a degree or two? Mines at 53...... which indicates unwanted circulation in the LLH probably from heating return.... but HR is 46..... and boiler return is 49....measured with installed thermocouples (my plumber wouldn’t know what a thermocouple is....)
Where the hell is the hot water going?
Boiler is pumping at 2M/hr and each of the two zones are pumping at 1m/hr
LLH is vertical. Yes, it’s definitely plumbed correctly WRT flows etc.
Pic to follow. P155 taking of the pipework is not allowed - it was done in a hurry in a listed building with asbestos preventing access to pipes etc. And we put in 14 bathrooms in 5 months (half into new spaces) at the same time. And CH....
Oh - and hello, my name is Guy and I’m not a plumber. ;-)
I have a large holiday let, in rural Somerset, and commercial heating engineers are rare out here. I’m a design engineer by education, so have taken on the task of getting this system running better than it is at the moment.
Long story short, the heat isn’t going where I expect and want it to go.
System comprises of a Grant oil boiler - 58/70 feeding a LLH six feet away. The primary is pumped with a digital variable speed DAB pump. The secondaries are pumped / zoned with similar DAB pumps.
Surely, when the heat load is large, eg on startup, the LLH should almost ‘not be there’ from a heat point of view? IE the hot from the boiler flow (at 74C) should pretty much be the flow to the rads? Plus or minus a degree or two? Mines at 53...... which indicates unwanted circulation in the LLH probably from heating return.... but HR is 46..... and boiler return is 49....measured with installed thermocouples (my plumber wouldn’t know what a thermocouple is....)
Where the hell is the hot water going?
Boiler is pumping at 2M/hr and each of the two zones are pumping at 1m/hr
LLH is vertical. Yes, it’s definitely plumbed correctly WRT flows etc.
Pic to follow. P155 taking of the pipework is not allowed - it was done in a hurry in a listed building with asbestos preventing access to pipes etc. And we put in 14 bathrooms in 5 months (half into new spaces) at the same time. And CH....
Oh - and hello, my name is Guy and I’m not a plumber. ;-)