House taking 6 hours to heat up 4 degrees? 16 December 2022 at 11:50AM edited 16 December 2022 at 11:50AM in In my home (includes DIY) MoneySaving 16 replies 1.1K views

beckstar1975

I am prefacing this by saying we are very lucky as we fixed our energy before the crisis

I think something is amiss with our heating - it's been on continually since 4am when it was 15.8 degrees and now it's only 18.2 degrees. Does this mean our rad temp is too low on the boiler? Or perhaps rads full of sludge? The boiler is 16 years old but is a Vaillant Ecotec in a 3 bed terraced 2 storey house.

Many thanks for any light shed!

RobM99

What's the thermostat set to?

housebuyer143

beckstar1975 said:

I am prefacing this by saying we are very lucky as we fixed our energy before the crisis

I think something is amiss with our heating - it's been on continually since 4am when it was 15.8 degrees and now it's only 18.2 degrees. Does this mean our rad temp is too low on the boiler? Or perhaps rads full of sludge? The boiler is 16 years old but is a Vaillant Ecotec in a 3 bed terraced 2 storey house.

Many thanks for any light shed!

It's very very cold outside. My house is normally a nice temp after 3 hours in the morning but the moment it goes off my hands are frozen. Having to keep it in much longer just to take the chill off. 
Its -4 outside. It's going to be hard to heat the house at the moment.

beckstar1975

RobM99 said: What's the thermostat set to?

19.5 whilst we're home but it never gets there (perhaps in the evening when we're all at home and the oven is on

ThisIsWeird

beckstar1975 said:

I am prefacing this by saying we are very lucky as we fixed our energy before the crisis

I think something is amiss with our heating - it's been on continually since 4am when it was 15.8 degrees and now it's only 18.2 degrees. Does this mean our rad temp is too low on the boiler? Or perhaps rads full of sludge? The boiler is 16 years old but is a Vaillant Ecotec in a 3 bed terraced 2 storey house.

Many thanks for any light shed!

A lot more information required, Beckstar.

1) Do all the radiators feel 'hot'? Can you keep your hands on them, or is it too 'ouch'?

2) Are they hot all over? Or are they much cooler near their bottoms?

3) Do they have TRVs fitted, and what are these set to?

4) How many radiators do you have calling for heat at the same time? Do you adjust them to actual need - ie turn off the bedrooms when they are not required (usually only needed for a one-hour blast before bed, and the same again before getting up, and 'off' (ie '1' or '2' at all other times). Any unused bedrooms which shouldn't have the heating coming on at all (apart from at 'frost')?

5) Where is the room thermostat fitted? I presume this is the area that doesn't reach much more than 18oC? But what about the 'living' area - does that get warmer?

6) What is the CH output set to on your boiler?

EssexExile

Ours is the same at the moment. The heating comes on at 6:30, by 9:00 it's about 16°, it got to18° about noon. It'll be fine next week!

greensalad

Ours is the same at the moment. House is normally about 14c when it comes on at 3pm. It doesn't reach our desired 18c by 11pm, only managed to get to about 16c! 

JGB1955

Our boiler is struggling to maintain 19c today - it's not normally a problem but it was particularly cold last night here.

Mutton_Geoff

It's been a lot colder than the design standard (BS EN 12831-1:2017) allows for. Not surprised people are complaining about their houses being cold. It's been sub zero for much of the country for most of the time since the evening of 7th Dec so that's 2.5% of the hours in a year already in this event alone.

ComicGeek

Mutton_Geoff said:

It's been a lot colder than the design standard (BS EN 12831-1:2017) allows for. Not surprised people are complaining about their houses being cold. It's been sub zero for much of the country for most of the time since the evening of 7th Dec so that's 2.5% of the hours in a year already in this event alone.

I was talking to a local ASHP company last week who admitted that they don't allow any heat up margin on their design calcs, and make the assumption that the heating is operating 100% of the time at the design temperature to keep the system as small as possible. I wouldn't want to be living in one of those houses at the moment, when we've been having -5/-6 degrees during the day this week - not only will the house not be able to get to temperature, even running it 24/7 will result in a gradual drop in temp.

Mutton_Geoff

ComicGeek said:

I was talking to a local ASHP company last week who admitted that they don't allow any heat up margin on their design calcs, and make the assumption that the heating is operating 100% of the time at the design temperature to keep the system as small as possible. I wouldn't want to be living in one of those houses at the moment, when we've been having -5/-6 degrees during the day this week - not only will the house not be able to get to temperature, even running it 24/7 will result in a gradual drop in temp.

I do live in one. Been using 75-90 kw/hr per day over the last week and as with ASHP and UFH, leave it on all the time. Fortunately only paying 18p a unit (£15 a day). Four bed 2600 sq ft, feeling nice and toasty.