How long to heat your house

System

ajbell wrote: »

The house is only heated in the morning as I don't get home until midnight, that's why its very cold in the morning.
House is 15 years old. All radiators work fine and get hot all over.

As I said earlier, your problem is most likely the size of your boiler. It is big enough to maintain a temperature but it is not big enough to heat a cold property to a decent temperature quickly - particularly, if a fair chunk of the boiler heat is being diverted to heat a HW cylinder. I am not suggesting that you need to change your boiler: all that is needed is an earlier boiler on time and, if possible, time your water heating outside of the time when you need CH in the morning.

Pincher

ajbell wrote: »

The house is only heated in the morning as I don't get home until midnight, that's why its very cold in the morning.
House is 15 years old. All radiators work fine and get hot all over.

So no one else in the house?
You can turn down the heat to rooms you don't use, and close the doors.

matelodave

Try this whole house heating calculator which will give you a very rough idea of the boiler size you's need to keep your house at around 19 degrees when its about zero outside. http://calculators.baxiknowhow.co.uk/boiler-sizing/ There are also on-line calculators which can do it on a room by room basis and tell you the sizes of radiators required.

However as Hengus says, it takes time to get up to that temperature and the radiators have to be sized to be able to dissipate all the heat that the boiler can produce.

If you are letting the both the house and hot water get fairly cold then you'll need to revise your timer settings so you aren't trying to heat them both at the same time. You could try just setting back the room stat to say 15 degrees during the day/overnight so the house doesn't get stone cold.

A programmable thermostat would allow you to set different temperatures at different time of the day and on different days of the week which would allow you to optimise the the heating so it's keeping you warm when you need it.

Raxiel

ajbell wrote: »

The house is only heated in the morning as I don't get home until midnight, that's why its very cold in the morning.
House is 15 years old. All radiators work fine and get hot all over.

The radiators may get hot, but its still possible that they are undersized for the house and unable to radiate enough heat from the water to the rooms, although I agree with Hengus that it's probably down to the boiler being on the small size.

But if the rads were sized to the boiler, then its possible the whole system would need upgrading if prompt heating was desired. Whoever installed it may have just intended it to be on at a low level most if not all of the day.

C_Mababejive

I wonder what control systems are on the OPs heating system?

I think the ideal would be a dual channel seven day programmer with twin zone valves or a diverter valve.

I would suggest OP sets programmer to initiated hot water only heat up a few hours before getting up for maybe an hour, and then initiate heat only beofre getting up.

Essentially, ensure that the boiler mostly does one or the other but try to avoid having it do both at the same time especially from cold.

The boiler does seem small to me. I have a two bedroomed home and have my boiler set to around 9Kw and it warms the house and hot water very well. The insulation standard is very good.