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Deleted member 99918

Boiler : Vokera Linea 25HE
Wireless Programmable Roomstat

I seem to have having major issues getting rooms up to a desirable temperature since moving into this flat.

It's an old 1920s tenement style building (ground floor 1 bedroom flat) with very high ceilings. Thick brick walls external and internal, uPVC double glazing.
I have the roomstat set to 21 for evening (comes on at 5pm, goes off at 10:30pm), overnight/during day set to 15.

So far i've never seen the roomstat hit 21 by the time 1030pm arrives (or at any other point during the evening). Usually sitting at around 18-19. So after being on for 6 hours it's never reached the desired temp. Rooms are always feeling on the cold side.

Rads are always hot to the touch during the peak time. TRVs are set to full on all rads.

Overnight when it's set to 15 the boiler is constantly kicking in for some minutes then going off again. I assume because it getting the temp back up to 15 then turning off, then the room temp is dropping quickly and thus the loop continues. The boiler is in the bedroom so this continual on/off loop is not great for sleep. I've had to set it so the boiler is off for heat overnight just to get a decent sleep.

So what is the issue here? Is the boiler just not up to the job? Are the rads too small for the rooms?
 
Potentially undersized rads. Need to get a heating engineer in to properly work out the heating rwquirements
 
the pipes feeding the rads is 8mm copper.
problem is, it's rented so trying to convince the landlord that their heating infrastructure is not suitable would be a tough ask.
 
I have the roomstat set to 21 for evening (comes on at 5pm, goes off at 10:30pm), overnight/during day set to 15.
[...]
So what is the issue here? Is the boiler just not up to the job? Are the rads too small for the rooms?

You're living in a building with a large thermal mass and are trying to heat it by running the heating for a five and a half hours a day. Try increasing the day/night temperature to, say 18, and then increase the setpoint to 21 around 1500hrs and then down again to 18 about an hour before you go to bed.
 
well the heating isn't running for just 5.5 hours a day though?
even when set to 15 the boiler is constantly coming on and off, so it's still running?

should it be able to get to 21 from a starting point of 15 in 5.5 hours?

i'm at the point where i honestly can't have the boiler on at all during the night because of the noise of it constantly turning on and off.

it's already eating huge amounts of gas as it is. i can only imaging having it at 18 as a base level will result in the bills climbing astromically.
 
should it be able to get to 21 from a starting point of 15 in 5.5 hours
I would think so, but it's impossible to be sure without knowing the dimensions and construction of the flat and the size of the radiators. If the radiators come on, the temperature rises at at reasonable rate to 18 /19 and then, with the radiator(s) 'ouch hot', it sticks at 18/19, then the likely explanation is that the radiator(s) are undersized.

If you have stored hot water, the constant turning on and off could be due to that part of the system. It's also possible that there is something wrong with the valves/controls so that whenever the heating is on the hot water tank is receiving flow and 'stealing' heat. Do you have a hot water tap that is dripping somewhere?

There are many possibilities hence RIley's excellent recommendation to get a heating engineer in to review (or repair) the system.

It seems to me that your real problem is with your landlord. I'd try to get that sorted first.
 
no, not stored water.
it's a combi so provides both heat and water. (on-demand).

there's no "problem" as such with the landlord. just wary about telling them their existing system is rubbish. as you'll know trying to convince any landlord to spend money is a tough job.
 
no, not stored water.
it's a combi so provides both heat and water. (on-demand).

There's a setting on many combis usually called something like 'instant heat', 'standby hot water', etc. that keeps a few litres of water hot continuously. This is nice but (a) the boiler keeps firing up to keep it hot, which matches your description, and (b) wastes a lot of gas, also consistent with your description. Switching it off may be called 'Economy hot water', setting.

Switching if off, won't fix the 'room too cold' part of your problem but should cut the bills and let you get a good night's sleep. You will have to run your hot taps for a few seconds longer before the hot comes through with it off.
 
don't think mine has a setting like that.
and if it did it can't be on, as it takes about 10-15 seconds of the tap being on before it's hot.

when the boiler is set to summer mode (ie water only) it stays completely off until a tap is opened.
 
i've set it come on a bit earlier now, and it's now getting to 21 by the evening.

it's chewing thru gas though.
 
it's chewing thru gas though.
One common reason for ridiculously high (apparent) gas consumption is submitting readings in cubic ft to a supplier who thinks they're in cubic meters.) Can you take two measurements of your gas meter reading 24 hours apart, please? Also photograph the meter at the time of each reading and upload the photos.

Another useful check is to switch the heating off for a period of several hours in the early evening and make sure that the meter doesn't change during the period. This checks that you are reading the correct meter and it is supplying only your flat. Obviously, you need to do this at a time when other people are likely to be consuming gas; 24 hours is best, if you can stand the cold that long.
 
It's a pre-pay unfortunately, which was here before I moved in (no debt on it), so I can see how much money is being used (as opposed to having to read meter units).

I'm the only person here and the heating is generally completely off during the day when I'm at work (set to come at around 3pm at 18 ramping up to 21 at around 530pm then off again at 10pm).

So from 10pm until 3pm the following day the boiler is off).
 
New double glazing recently installed.
Insulate what? It's thick brick walls, it'd need to internal wall insulation which is unrealistic.
 
It's a pre-pay unfortunately, which was here before I moved in (no debt on it), so I can see how much money is being used (as opposed to having to read meter units).

How much is it charging you (per cubic metre or ft) for the gas? How much does is it costing per day?

If you don't provide actual figures, we can't check that whether they are reasonable or not.
 
I'll need to see how to get the meter to tell me the chargeable rate. Pressing button A just shows current debt (£0), meter index, and current balance. Button B doesn't seem to show anything.

It's used over £5 in 36 hours (but it's not been on for all of those 36 hours).
 
I'll need to see how to get the meter to tell me the chargeable rate. Pressing button A just shows current debt (£0), meter index, and current balance. Button B doesn't seem to show anything.

It's used over £5 in 36 hours (but it's not been on for all of those 36 hours).

You need to find out from the gas supplier what tariff you are on. I suspect you're just being charged a lot per kW hr.
 
3.843p / kWh
24.56p standing charge per day

So, let's estimate that your heating was on for 2 * 7-hour periods during the 36 hour it cost £5. That means that while the heating as on it was consuming:

(500 p - 36/24 *24.56 p) / (3.843 p / kW hr) / ( 2* 7 hr ) = 8 kW

You would need about 6 hot radiators (4 ft W * 2ft H) blasting away to dissipate that much heat, more than I'd expect for a small flat with reasonable insulation at this time of year.

So, I wonder if you have a dripping hot-water tap or possibly a leak somewhere. This would explain your observation that the boiler is continually firing up throughout the night.
 
The boiler doesn't do that any more now that it's off during the night.

And no dripping taps.

5 rads in total in flat. Living Room, kitchen, bedroom, bathroom and hall. They are all single except for the living room which is a double.

The only other time something would be using gas is when the oven is on for dinner.
 
5 rads in total in flat. Living Room, kitchen, bedroom, bathroom and hall. They are all single except for the living room which is a double. The only other time something would be using gas is when the oven is on for dinner.

The gas oven is only going to be less than 10% of the total.

8kW for 7 hours a day is on the high-side but not impossible particularly if the adjacent flats are unoccupied.

It's possible that the meter is actually charging you more than 3.8p/ kW hr so you need to find out what volume of gas it is recording.

The explanation could simply be that you are living in a flat with very high heat losses and the rent should be lower to reflect this.

The only way to be sure would be to get a heating engineer to do a heat loss calculation, check the calibration of the meter and that system is operating correctly.
 

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