System boiler flow temperature fluctuates wildly
- Thread starter molgrips
- Start date
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I don't know about there, but here I have been avoiding running the CH - I've just fired up the gas fire in the living room on an evening and not even every evening. House is holding around 18C, even with no CH.
Right, next time it fires up watch the flow temperature closely and see does the burner shut down (you may have a flame signal on the boiler front), once the flowtemp exceeds 55C.
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I'm in Yorkshire, in the foothills of the Pennines. I'm in an early 1990s detached house, well built, but insulation standard for the era.
Without heating the house would have been below 15C these past few weeks. Sometimes well below.
Not that far from me then, but I don't quite understand your heat loss. Mine is a mid 50's semi, which I have DG'ed and CWI'ed, I am at a local high point too.
When I moved in, in the 80's it was SG'ed, almost no insulation, no CH just a gas fire, which had replaced a coal back boiler, to heat just the water. It used to have ice on the insides of the windows, we could never get the place warm. All very different now.
I have four thermometers all reading within 0.1C of each other. And the digital thermostat doing the same. So, I think my data is good.
I'm really confused. The local 24 hour average temperature has been about 11C over the past three or four weeks. How can your house be 18C? I know there's some solar gain sometimes during the day, but that surely isn't enough. I've noticed a few other posters whose houses are still really warm without heating.
EDIT: 24 hour average closer to 10C than 11C I think. The past few days have been a bit warmer than the weeks before.
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An adult doing nothing emits about 100W I was told. Two of us in the living room plus the TV and the modem/WiFi router is probably about 450W of heat output. Most of the year this alone is enough to heat the room with the door to the hallway closed. If the heating is on in the rest of the house then the TRV shuts off and we still have to open the hallway door otherwise we get too hot.
That's really interesting. And very different to my house. You mentioned your house is well insulated. Have you done things over and above the building regs level?
EDIT: I'm using about 5 KWh of electricity a day. Does that count as heating? It's not actually been used for heating. Mainly fridges and freezers I think.
We added an extra layer of loft insulation, so it is now about 60cm thick. Then we've fitted heavy curtains and a curtain with a portiere rack on the front door. We've also sorted a few draughty spots like the window frames and we sealed a gap around the living room window with some expanding foam. It all helps.
There are 6 pips on the temperature control knob, and the manual says it goes from 30 to 80C. So logically, each pip should be 10C and I've attached a picture of where I had it set which should be 50C.
So I fired up the hot water and watched the temperature control. It throttled back (modulated) at 69C when the return temperature was 59. Then the temperature gradually fell to 67C with the return temp at 60C at which point it shut off.
Surely this is not working correctly? The temps fell to the mid 40s which was the temperature in the tank, and the burner didn't come back on at all.
Attachments
See the graph below. Yellow line is indoor temperature, in a cooler part of the house, actual is a degree or so higher. Blue is the outdoor temperature, Green the dew point.
Sharp step up at 13:30 23rd, is due to solar gain. There has been no CH on at all so far this autumn, just the living room gas fire sometimes on an evening, which is remote from the temperature sensor, so it doesn't see any warmth from the gas fire. It would see heat from the CH.
I agree, but not with 100w when not active. I would say around 25w per person, sat relaxed.
TV around 70w, unless it's something special, router 2w of waste heat. I'm doing a bit of research here, on heating just my living room with my radiant gas fire, rather than the whole place up...
Door to hall closed, with fire on 1kw it warms up very rapidly, I have to soon drop it to 500w, even that is too much. It is quoted as being 86% efficient.
Average E consumption is 5.6Kw per day, I'm fully LED, but I have 4x routers running continuously, various things on standby, lots of gadgets running, plus the usual things. It varies little, winter to summer. Much of that will appear as heat in the house, but not all consumption is inside.
Gas at the moment is averaging 14kwh, which is all cooking, all water heating (except electric shower), and a bit of heat sometimes in the evening.
I had a bath this morning, immediately after the gas boiler had fired to bring my cylinder up to 60C. My system logs exactly what and when it is used constantly, so after my bath I was able to check how much gas it had burned bring my cylinder back up to 60C - it claimed to cost 2.86Kwh and 29p to recover.
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That does not seem correct, can you ensure all rads are calling for heat, may have to increase roomstats SP and open TRVs fully and repeat that test with no HW request.
Great data. What sort of set up is that?
My house is bang on 17C today, and so far I've used 10KWh of gas on heating. That should be it for the day. My boiler is really old.
I think my heat loss must be because it's just me in a big house, and it's detached, which I think loses 25% more.
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