Which is more economical for me?

ARainyDay

Hi all, recently moved into a rented detached house. Prior to moving I believe it had been vacant for 1-2 months. There's double glazing, 100mm pitched loft insulation, cavity wall, TRVs on rads and thermostat. It can be draughty in some rooms (I'm working on that!), but it is very cold, and there are some signs of damp. In the morning, without any heating the bedroom can be at 12.5 degrees. The boiler is recent, but the radiators are undersized for the space (engineer who was addressing another problem advised on this). The room with the biggest one took 2hours to go from 12 degrees to 16 with the thermostat just on manual, TRV at 3 and boiler flow at 4 out of 6. I didn't rely on the thermostat for this reading but used a room thermometer. Once at 16 it didn't get any warmer, and I am yet to achieve a temperature beyond that. I have been gifted a dehumifier, as there is high humidity upstairs, so I'm hoping that might make it easier for the air to heat once moisture is gone (?). It almost seems pointless running a thermostat (which is in a good position in the kitchen) as the temperatures never reach the desired heat, and even putting it to an 'off' temperature I feel like the boiler would be firing all day and night if I set it to 13.5 degrees, as temperatures drop so quickly here the usual ambient temperature is around this mark anyway. Would it just be cheaper for me to turn the heating on manual for some time in the morning and evening, even if it meant crawling up a few degrees (which I understand would take some time), instead of having it chugging away trying to maintain a temperature all day (even if that temperature is low). I hope I've explained the situation properly!

InvertedVee

I would try some experiments and this cold snap is a good time to do it. It'll cost a few quid but you'll know where you stand and what kind of improvements are needed.

Before that, what's your EPC rating? Note a bill is in parliament that would require from 2025, all newly rented properties to have an EPC rating of C or above. This would apply to existing tenancies from 2028. So your landlord should be aware and planning improvements if not at C already. You might be able to persuade them to hurry up!

Now for an experiment...

Take a gas meter reading. Get the house nice and warm (say 19C) and dry (under 60% relative humidity) by setting the room thermostat to 19C and running the heating constantly, with a boiler flow of 4 out of 6, setting all the TRVs to 4 and running the dehumidifier. This may take 1-2 days and cost a few pounds but you'll get to a position where you can start to make sense of what's actually going on. I would be surprised if you're unable to raise the room temperatures above 16C once the fabric has been properly heated and dried. And if you can't maintain the 18C recommended minimum for health, the landlord could be failing in their legal obligation to provide an adequately functioning heating system (but you'll need to take proper advice on that).

If you've reached the 19C warm and dry starting point, carry on...

Take another gas meeting reading and set the night-time temperature to 17C, leaving the day temperature of 19C.

Take another gas meter reading on the second day. If your property is reasonably insulated, you should find that in the morning the house will reach 19C in a couple of hours. If it's much shorter than that, reduce your flow temperature to 3.5 out of 6. If it's much longer than that, increase your flow temperature to 4.5 out of 6.

You might need to do a third or even fourth day, taking gas meter readings every morning at the same time. But you'll find out a huge amount by doing this, and you will have found the lowest (most efficient) boiler flow temperature to maintain the room temperature settings. You may learn that your thermostat is in the wrong place (a common problem).

And most valuably, you'll have an accurate idea of how much energy your home actually requires to maintain the 17C/19C split in the coldest weather. You might decide that this is a cost you can bear. You may also find that you can accept 16C/18C. But if your tempted to let the whole house or some rooms to go cold for periods you'll find that you'll need to run the boiler at a much higher flow temperature and you may never really feel comfortable. And the damp will cause mould and risk your health.

There are a range of improvements that can be made, including increasing radiator sizes as the engineer suggested, but you really need a good starting point.

Olly_J

You can read a study that was done to try and measure the different timing methods of heating usage

https://www.beama.org.uk/static/c8acda90-4bf0-4d1d-9f388667190a1c84/Salford-University-tests-to-establish-the-energy-savings-from-Prog-room-thermostats-2014.pdf

Essentially in the test, setback compared to standard Off/On was found to be only 3% more in their tests.

I use a setback method and I find its using the same amount of gas as when i ran on off, given how long it takes to reheat from cold, and it makes for a far more comfortable house with no condensation issues.

FreeBear

ARainyDay said: The room with the biggest one took 2hours to go from 12 degrees to 16 with the thermostat just on manual, TRV at 3 and boiler flow at 4 out of 6. I didn't rely on the thermostat for this reading but used a room thermometer. Once at 16 it didn't get any warmer

Not all TRVs are created equal. If your room temperature didn't climb above 16°C, I'd turn the TRV up to 4 or even Max - It won't make the room heat up any quicker, but should allow the temperature to get above 16°C.

Pester your landlord for more loft insulation. An extra 200mm up there won't cost a huge amount, but it will score him an extra point or two on the EPC and save you a little on heating. It won't cut the heating costs a huge amount (maybe ~£30 per year)..

ARainyDay

M0KBJ said:

I would try some experiments and this cold snap is a good time to do it. It'll cost a few quid but you'll know where you stand and what kind of improvements are needed.

Before that, what's your EPC rating? Note a bill is in parliament that would require from 2025, all newly rented properties to have an EPC rating of C or above. This would apply to existing tenancies from 2028. So your landlord should be aware and planning improvements if not at C already. You might be able to persuade them to hurry up!

Now for an experiment...

Take a gas meter reading. Get the house nice and warm (say 19C) and dry (under 60% relative humidity) by setting the room thermostat to 19C and running the heating constantly, with a boiler flow of 4 out of 6, setting all the TRVs to 4 and running the dehumidifier. This may take 1-2 days and cost a few pounds but you'll get to a position where you can start to make sense of what's actually going on. I would be surprised if you're unable to raise the room temperatures above 16C once the fabric has been properly heated and dried. And if you can't maintain the 18C recommended minimum for health, the landlord could be failing in their legal obligation to provide an adequately functioning heating system (but you'll need to take proper advice on that).

If you've reached the 19C warm and dry starting point, carry on...

Take another gas meeting reading and set the night-time temperature to 17C, leaving the day temperature of 19C.

Take another gas meter reading on the second day. If your property is reasonably insulated, you should find that in the morning the house will reach 19C in a couple of hours. If it's much shorter than that, reduce your flow temperature to 3.5 out of 6. If it's much longer than that, increase your flow temperature to 4.5 out of 6.

You might need to do a third or even fourth day, taking gas meter readings every morning at the same time. But you'll find out a huge amount by doing this, and you will have found the lowest (most efficient) boiler flow temperature to maintain the room temperature settings. You may learn that your thermostat is in the wrong place (a common problem).

And most valuably, you'll have an accurate idea of how much energy your home actually requires to maintain the 17C/19C split in the coldest weather. You might decide that this is a cost you can bear. You may also find that you can accept 16C/18C. But if your tempted to let the whole house or some rooms to go cold for periods you'll find that you'll need to run the boiler at a much higher flow temperature and you may never really feel comfortable. And the damp will cause mould and risk your health.

There are a range of improvements that can be made, including increasing radiator sizes as the engineer suggested, but you really need a good starting point.

Thanks very much for this- I've started this experiment, and am surprised to find that some of the rooms are now going beyond 16 degrees, so I'll keep the heating going until the thermostat reaches 19 degrees. I only have a very small dehumidifer going, as I am still waiting for the large one to arrive, but humidity has already gone down. I can see the price climbing- to have 4 radiators (all with fins, 2 single, 2 double) and a towel rail going, I've used 20.60 kWh in 3hrs 15 mins, which @ 12.94p/kWh is equal to £2.66, and for example during this time the bedroom temperature has gone up 4 degrees. Is this considered expensive or usual? I've only previously lived in a small flat which required little to no heating

Mstty

I suspect the aforementioned bill going through parliament for all rentals to be EPC C by 2025 for new tenants may take far too much old housing stock off the rental market and create a bigger problem than there is now for renters.

It will be interesting how watered down or changed it becomes.

Alnat1

Thinking of all the single brick 100-150 year old terraced houses in the northern towns around here, it would cost landlords way too much to bring them up to C.

My daughter bought an end terrace a couple of years ago and I've looked up the EPC. It is rated E, fully double glazed, has a modern boiler and heating controls and LED lighting.

To raise that to C the EPC says she would have to insulate the attic bedroom at a cost of £3-5K, internal/external wall insulation £6-18K and insulate under living room floor (cellar ceiling) £2-4K. That would give a score of 70, just scraping into a C. The costs have probably gone up over the last 2 years too.

So £11-27K spend on a property now valued around £105K. If that was a rental, the landlord would probably sell it.

FreeBear

Mstty said:

I suspect the aforementioned bill going through parliament for all rentals to be EPC C by 2025 for new tenants may take far too much old housing stock off the rental market and create a bigger problem than there is now for renters.

It will be interesting how watered down or changed it becomes.

At a guess, it will be possible for landlords to apply for an exemption certificate for the first 5 years (for a fee).

InvertedVee

...I've used 20.60 kWh in 3hrs 15 mins, which @ 12.94p/kWh is equal to £2.66, and for example during this time the bedroom temperature has gone up 4 degrees. Is this considered expensive or usual?

1. I'm not surprised that it's taken 20.6kWh to boost the temperature of a cold and damp house. It's going to take some time for the heat to penetrate the fabric of the building and to lift out the moisture. You'll need to be patient to reach the warm, dry starting point and it might cost you a tenner to get there. The rate of gas consumption will reduce over time.

2. I pay 10.334p per kWh for gas, including VAT, under the energy price guarantee. Not sure why you're paying 25% more.

Looking forward to hearing your figures tomorrow.

InvertedVee

Alnat1 said:

Thinking of all the single brick 100-150 year old terraced houses in the northern towns around here, it would cost landlords way too much to bring them up to C.

My daughter bought an end terrace a couple of years ago and I've looked up the EPC. It is rated E, fully double glazed, has a modern boiler and heating controls and LED lighting.

To raise that to C the EPC says she would have to insulate the attic bedroom at a cost of £3-5K, internal/external wall insulation £6-18K and insulate under living room floor (cellar ceiling) £2-4K. That would give a score of 70, just scraping into a C. The costs have probably gone up over the last 2 years too.

So £11-27K spend on a property now valued around £105K. If that was a rental, the landlord would probably sell it.

Thanks @alnat for those stark figures. The energy crisis and housing crisis are horribly interlinked.

chris_n

I have a rental property that I lived in for 30 years until Brexit forced my hand and I moved to Austria. I got an EPC for it last year and it came out as a D. I have looked at all of the same type of properties in that street and found EPC's ranging from B to E. Some of the worse ones still have old windows and no loft insulation. Of the better ones only one has newer windows but they will still be 10 years old so not latest spec, none have any more insulation than mine (cavity wall and 300mm loft), none can have more than 100% LED lighting. Fair enough my boiler just predates condensing boilers ( hardly been used for the last 10 years as I haven't been there in winter) but mine does have solar panels!

Strikes me the system is a joke when such differences in assessment and the comments in the EPC's can be so different for identical houses. One EPC even says the brick and block construction is timber framed!