Cost effective ways to run underfloor heating.

Zoola

we have a wet under floor heating system we put into our house in 2010. Everything we read says that the heating should be on constant and that once the optimum temperature is reached it doesn't take a lot to keep the temperature constant.

My husband has insisted that we should put the heating on a timer and have it on for 2-3 hours in the morning and 2-3 hours in the evening. We have never successfully heated the house to a comfortable level and its quite expensive to run.

I have now taken the reins and put the heating on constant. the thermastats are set at 18-20 in the rooms we use downstairs, off in the rooms we don't use and there is no heating in the bedrooms.

We have been comfortable throughout the house for the first time, however the oil consumption is frightening. We calculate that 1'000 litres will last us just 30 days.

Is there a better way? Should we turn off at night and run constsntly during the day? Reduce thermastat considerably. We don't have a wood burner to supplement the heating

Or is the reality of oil fired under floor heating such that to achieve the ideal temperature you have to spend a fortune?
(we have no loft insulation and cavity walls are not insulated, we do have a lot of glass but it is all triple glazed. (we have bought insulation and scheduled to fit!)

lovesgshp

Zoola wrote: »

we have a wet under floor heating system we put into our house in 2010. Everything we read says that the heating should be on constant and that once the optimum temperature is reached it doesn't take a lot to keep the temperature constant.

My husband has insisted that we should put the heating on a timer and have it on for 2-3 hours in the morning and 2-3 hours in the evening. We have never successfully heated the house to a comfortable level and its quite expensive to run.

I have now taken the reins and put the heating on constant. the thermastats are set at 18-20 in the rooms we use downstairs, off in the rooms we don't use and there is no heating in the bedrooms.

We have been comfortable throughout the house for the first time, however the oil consumption is frightening. We calculate that 1'000 litres will last us just 30 days.

Is there a better way? Should we turn off at night and run constsntly during the day? Reduce thermastat considerably. We don't have a wood burner to supplement the heating

Or is the reality of oil fired under floor heating such that to achieve the ideal temperature you have to spend a fortune?
(we have no loft insulation and cavity walls are not insulated, we do have a lot of glass but it is all triple glazed. (we have bought insulation and scheduled to fit!)

If you have only just increased the heating to run continuously, the floor mass can take up to 24-48 hrs to get to temperature and then the boiler only has to start up as room temperature drops, so you should start to see a drop in oil usage.
You do need to increase the insulation level to get the maximum benefit. Your room settings seem ok, we are on 19.2C constantly here.

reeac

Zoola wrote: »

we have a wet under floor heating system we put into our house in 2010. Everything we read says that the heating should be on constant and that once the optimum temperature is reached it doesn't take a lot to keep the temperature constant.

My husband has insisted that we should put the heating on a timer and have it on for 2-3 hours in the morning and 2-3 hours in the evening. We have never successfully heated the house to a comfortable level and its quite expensive to run.

I have now taken the reins and put the heating on constant. the thermastats are set at 18-20 in the rooms we use downstairs, off in the rooms we don't use and there is no heating in the bedrooms.

We have been comfortable throughout the house for the first time, however the oil consumption is frightening. We calculate that 1'000 litres will last us just 30 days.

Is there a better way? Should we turn off at night and run constsntly during the day? Reduce thermastat considerably. We don't have a wood burner to supplement the heating

Or is the reality of oil fired under floor heating such that to achieve the ideal temperature you have to spend a fortune?
(we have no loft insulation and cavity walls are not insulated, we do have a lot of glass but it is all triple glazed. (we have bought insulation and scheduled to fit!)

There are maybe 3 ways to reduce your heating bill:
1. insulate.
2. shop around for best fuel tariff.
3. reduce your house temperature.
You can do the last one by switching off the heating when you don't need it e.g.when you're asleep or out of the house. Unfortunately this isn't compatible with underfloor heating as the time constant for a floor slab is so great however it's fuelled.

At least you can look forward to considerable savings once your roof and walls are done.

aelitaman

When you had the UFH installed how much insulation was put underneath?

malc_b

1000 l a month is a vast amount. Is this based on just a few days? My 5 bed house uses about 1500 l per year. Mine is fairly well insulated but not as good as modern standards. If you are basing the month usage on a few days I'd say note the usage each day and see whether this drops off after a few days when the house fabric has warmed up.

Also, this heating up effect you'll see to some extent with any type of heating. What most people don't understand is the heating process. If the inside of the house is warmer than outside then the house is losing heat to the outside. So when the heating is off, if the inside temperature is still higher than outside you are still losing heat (i.e. overnight). This is coming from the fabric of house and is a debt you have to pay back when you turn on the CH again. The shorter you have the heating on the harder you have to drive the heating. Where overnight the temperature inside doesn't drop much then the rate of heat lost by the house also doesn't fall by much either. So there is not a lot of saving to be made by shorter on times.

Another point to consider is that most house insulation is in the outside shell. There is little insulation between rooms. So turning off radiators in rooms just means that these rooms have to heated by the radiators still left on. That means those radiators have to be hotter to give out more heat which is less efficient.

As well as more insulation I'd look at how your oil boiler is running. It is short cycling, which is inefficient or is it having a nice long continuous burn? I have a fixed time controller for mine which gives one burn every 15 minutes, i.e. 7.5min would be 50% power to give you an idea of the burn time you're looking for.

reeac

malc_b wrote: »

1000 l

Also, this heating up effect you'll see to some extent with any type of heating. What most people don't understand is the heating process. If the inside of the house is warmer than outside then the house is losing heat to the outside. So when the heating is off, if the inside temperature is still higher than outside you are still losing heat (i.e. overnight). This is coming from the fabric of house and is a debt you have to pay back when you turn on the CH again. The shorter you have the heating on the harder you have to drive the heating. Where overnight the temperature inside doesn't drop much then the rate of heat lost by the house also doesn't fall by much either.So there is not a lot of saving to be made by shorter on times.

Quite misleading! The rate of loss of heat from a house is proportional to the difference between inside and outdoors temperatures. Savings due to switching off are due to the indoor temp. falling and thus reducing the rate of heat loss. The comfortable way to do this is to switch off when you're in bed or out of the house. These heat savings do NOT have to be fully paid back like money taken from a bank account - you have to expend enough fuel to get the place up to temperature again and that's a different and smaller amount.

J_B

Zoola wrote: »

Is there a better way?

We've had UFH for the last 6 years - still haven't got the hang of it

Our room thermostats (we have one in most rooms) are set at various temperatures.
Some are as low as 14 and one is as high as 24 - maybe you need to 'mess' with them to get the best. Keep turning them down till the other half complains, that's what I do

All our 'stats have a 'moon' setting on them (is it called kick-back?) these are connected to the main timer and if set to the moon, then the temp will reduce by X degrees (which you can set) at Y times (which you can set) .
Keep messing till you get the better of it, but get that insulation fitted PDQ!

Swipe

1000 litres in 30 days is horrendous! This is also compounded by the fact that the last few weeks have been unseasonably mild too.