Heating takes ages to heat up - small house

vic_sf49

rosamy52 said:

The boiler is a Duo Baxi boiler. The thermostat (a portable one) was supposed to be at 13 overnight this morning but it hadn't gone on, probably me not setting something properly, but it was 10.5 and it took an hour to go up 1.5 degrees. Even if it's on for four hours in the evening it rarely gets to 18 degrees. The radiators seem fine, there are no valves apart from on one upstairs.  The boiler radiator temp is set to 65. I don't think I can afford to have the heating on more than I do. 

I'm not sure if anything is wrong or if it's just slow or if something is wrong. Any pointers of where to start would be super helpful or should I just get in touch with the lettings agency straight away? 

My system heated up my bungalow* at 1.34 degrees per hour this morning, and I think that's normal.

*3 bed detached bungalow, epc B. Boiler flow temp on 5/6, which equates to 74 degrees.

(I normally have the flow temp a bit lower, when it's not so cold outside, and don't mind it taking longer to warm up.) 

ic

QrizB said:

ic said:

Try upping the temp

Turning up the flow temperature will increase the output of the radiators, meaning the boiler burns gas fadter. It'll also make the boiler less efficient, meaning it burns more gas.

As the problem is that the OP isn't prepared to spend more than £2 a day on gas, increasing the flow temperature is likely to make the problem worse not better.

Yup.  Bit of a catch-22.

Bigphil1474

1.34 degrees per hour isn't normal IME unless the starting temp is already high. My heating goes off at 9pm and comes on at 5:50am. I get up at 6:15am and the house is already around 19c. Last time I checked (NYD) that was from around 10c overnight. 

OP, I used to live in a mid terraced 1930s house with solid walls. Had no problem heating it and keeping it warm, and we only used to have the heating on for an hour in the morning and an hour in the evening. We had a fairly new boiler and all modern radiators (bar one in the box room), all with TRV's. Sounds like your heating system is rubbish. Are they all single radiators (thickness)? The double radiators are much better. We had a 2200mm one fitted in our living room just before Christmas and it heats up so quickly we had to move the thermostat out and adjust all the other radiators so the whole house heated up. Our newer house is better insulated fortunately, but even so, an hour of having the heating on should raise the temp sufficiently.

Vitor

Given OP's budget may be better to look at heating the person and not the whole house with an electric heating pad

QrizB

Bigphil1474 said:

 Last time I checked (NYD) that was from around 10c overnight.

That's crazy; even in the current weather it would take a week for my house to cool down that much.

Is your current house of modern lightweight construction? Wood framed or similar?

Albermarle

QrizB said:

Bigphil1474 said:

 Last time I checked (NYD) that was from around 10c overnight.

That's crazy; even in the current weather it would take a week for my house to cool down that much.

Is your current house of modern lightweight construction? Wood framed or similar?

I have an older house, so it would certainly go down below 10 degrees with no heating on for a week in this weather.
However I agree I would not expect it to drop down to 10 overnight !

I would estimate the hardest to heat rooms in our house (Kitchen, hallway and loft room) probably do only increase by 1/1.5 degrees an hour from when the heating starts in the morning. The more enclosed rooms will go up quicker

QrizB

Here's a chart for a temperature sensor in my house; we were away from the 21st to 29th of December, which wasn't as cold as this week's been. The heating was off (thermostat set to 12) and the temperature dropped from 18C to 12C.

silvercar

QrizB said:

Here's a chart for a temperature sensor in my house; we were away from the 21st to 29th of December, which wasn't as cold as this week's been. The heating was off (thermostat set to 12) and the temperature dropped from 18C to 12C.

If your heating was set to 12, the heating would have kept it to 12 or thereabouts.

when I went away in December it took 5 days for my heating to drop to 13 degrees. When I started reheating the house it was only gaining 1-1.5 degrees an hour as the fabric of the building was cold. Now it increases by about 2 degrees an hour in cold areas. In cosy rooms with the doors shut it will gain 3 degrees an hour easily.

QrizB

silvercar said:

If your heating was set to 12, the heating would have kept it to 12 or thereabouts.

Yes, that's how thermostats work.

However the house didn't fall to 12C until the seventh day and the boiler didn't run for any significant time during that period.

As it started at circa 18C, that's a much slower cooling than BigPhil's house.

silvercar said:

when I went away in December it took 5 days for my heating to drop to 13 degrees.

Similar to my experience. Not similar to BigPhil's.

silvercar said:

When I started reheating the house it was only gaining 1-1.5 degrees an hour as the fabric of the building was cold. Now it increases by about 2 degrees an hour in cold areas. In cosy rooms with the doors shut it will gain 3 degrees an hour easily.

Similar to mine and to the OP's house, but not the "9C in 25 minutes" that BigPhil is claiming.

ComicGeek

If the boiler is sized correctly, then around 80% of the boiler's output is intended to replace heat lost on the coldest day through the walls, floor, roof, windows, ventilation, air leakage etc.

The remaining 20% is needed to raise the room temperature, as the initial 80% purely offsets the losses - if you want to raise the temperature more quickly, or raise the temperature on really cold days, then this design margin needs to be increased. 

But if the heating system is designed to run at a flow temperature of 75 degrees, and it's dropped down to 65 degrees to save money, then the heating output has been reduced by 20% - that means the heating only offsets the losses and doesn't raise the internal temperature much if at all! If the heating isn't sufficient, then increase the boiler temp for just a few days. The adverts about turning down the boiler temperature are very misleading and give poor advice, as the savings are extremely small with gas boilers and likely to lead to poor comfort in winter.

At the moment you're spending 80% of the fuel cost and still being cold, and to me that's a waste. Either accept spending 100% and be warm, or spend much less and accept being cold (or go out, visit a friend, wear more layers, heat only 1 room etc).