Changing oil fired boiler – best overall solution??

rosscouk

I have just moved into an end of terrace Victorian house in the country in which the heating (11 radiators) and hot water is provided by a Stanley oil range. The house is in need of better insulation and I am working on that currently. My question at the moment is about changing the Stanley and what to do in terms of providing heat and hot water for the house. I was going to leave it to the spring and possibly until next year however the amount of oil we are using is phenomenal and I don’ t think I can wait that long. I filled up a practically empty tank with 500 litres two weeks ago and we are already more than halfway through the tank. So well over 100 litres a week. I know its winter but we only have the heating on from 5.50 am until 7.20 am and 5.00pm until 9.40pm and even then only on the lowest temperature setting on the Stanley (45). I have turned off the hot water as the tank is heated when the central heating is on and we have not run out yet (1 shower a day plus a few bowls of hot water for washing up).

The Stanley has been serviced and had some parts replaced but the amount of oil the 19 year old boiler is using is just not sustainable financially for me at around £300 a month. I had hoped to save up and replace next year but I think it will be cheaper to take a loan and replace now.

So, thinking about potential solutions I am focussing on the following;

• Replace the Stanley with a new oil fired internal combi boiler
• Decommission the Stanley, remove the current hot water tank and feeder tanks in the loft.
• Replace open fire in the living room with a wood/alternative fuel burner
• Insulate the house to the highest standard we can afford (loft already done – could double layer with insulation).
So does this approach seem sensible? I have some questions
• Will a new combi boiler be much more efficient than my Stanley?
• Should I get a combi boiler over a ‘normal’ boiler (traditional boilers seem a little more efficient)?
• What is the best boiler for this solution? Grant, Worcester – any thoughts on model?
• Should I change the fire and the boiler at the same time or change the boiler and see how it affects things?
• Is it worth double insulating the loft?
• Are there any insulation things that I must do?
• The jury seems to be out on alternative hear sources, my garden is too small for ground source heating and my wife feels air source heating is still to immature technology with out enough evidence that is would work for us given the expensive initial outlay, does anyone have any opinions?

Have I forgotten anything? Thanks for any comments.

Ben84

How much loft insulation do you currently have? 270 mm is I believe the current new build regulations and what most people who insulate their existing lofts are trying to install. I was curious about the benefits of adding more so did try to google it, but found nothing about the effect of going above this depth. What is clear however is that many sources suggest going from 0 to 270 mm saves a typical three bedroom mains gas heated house roughly £100-200 a year. However, insulation additions have sharply diminishing energy saving returns as the depth goes up. So, doubling for example 270 mm will not save this much again, the actual amount saved will have to be less, possibly quite a bit less. I'm curious if anyone else has an answer to this and will also consider how we might calculate it.

rosscouk

Thanks Ben84, that makes sense. I would suspect I have 270mm but not checked. I need to do a little more research I think. I know I can definitely do more to insulate my loft hatch, its basically a sheet of plywood with no insulation on the back of it, this must be a bit of an oversight!

[Deleted User]

rosscouk wrote: »

I have just moved into an end of terrace Victorian house in the country in which the heating (11 radiators) and hot water is provided by a Stanley oil range. The house is in need of better insulation and I am working on that currently. My question at the moment is about changing the Stanley and what to do in terms of providing heat and hot water for the house. I was going to leave it to the spring and possibly until next year however the amount of oil we are using is phenomenal and I don’ t think I can wait that long. I filled up a practically empty tank with 500 litres two weeks ago and we are already more than halfway through the tank. So well over 100 litres a week. I know its winter but we only have the heating on from 5.50 am until 7.20 am and 5.00pm until 9.40pm and even then only on the lowest temperature setting on the Stanley (45). I have turned off the hot water as the tank is heated when the central heating is on and we have not run out yet (1 shower a day plus a few bowls of hot water for washing up).

The Stanley has been serviced and had some parts replaced but the amount of oil the 19 year old boiler is using is just not sustainable financially for me at around £300 a month. I had hoped to save up and replace next year but I think it will be cheaper to take a loan and replace now.

So, thinking about potential solutions I am focussing on the following;

• Replace the Stanley with a new oil fired internal combi boiler
• Decommission the Stanley, remove the current hot water tank and feeder tanks in the loft.
• Replace open fire in the living room with a wood/alternative fuel burner
• Insulate the house to the highest standard we can afford (loft already done – could double layer with insulation).
So does this approach seem sensible? I have some questions
• Will a new combi boiler be much more efficient than my Stanley?
• Should I get a combi boiler over a ‘normal’ boiler (traditional boilers seem a little more efficient)?
• What is the best boiler for this solution? Grant, Worcester – any thoughts on model?
• Should I change the fire and the boiler at the same time or change the boiler and see how it affects things?
• Is it worth double insulating the loft?
• Are there any insulation things that I must do?
• The jury seems to be out on alternative hear sources, my garden is too small for ground source heating and my wife feels air source heating is still to immature technology with out enough evidence that is would work for us given the expensive initial outlay, does anyone have any opinions?

Have I forgotten anything? Thanks for any comments.

Regarding alternative hear sources... Our ASHP heats and does DHW through 1 towel rail rad, 13 fan convectors and ufh in the bathroom 24/7 for £100 pm in winter. Half that in the warmer months. This includes all other electric useage and we are not frugal. Large 1906 detached house with high ceilings and medium insulation levels.

Massive savings to had over LPG and oil with RHI on the horizon to sweeten the pill...

A Range is typically more greedy that and modern boiler but is it really worth the change say you go from £300 to £250pm? Everyone I meet on oil wants GSHP or ASHP

rosscouk

That's good to hear jeepjunkie, how much did it cost to install your system? Was it difficult to install underfloor heating? What ASHP do you have? Have you had any issues with it? What fan convectors do you have? Where are they fitted?

I don't mind considering ASHP although the initial installation costs really worry me, as any change will need to be done through a loan. Whatever I have read so far doesn't fill me with confidence regarding ASHP although I don't want to misstep by installing a new oil combi. I would hope if I did install a new combi it would save alot over the Stanley.

[Deleted User]

You have PM.

rosscouk

I am looking into ASHP, but I am not sure I can afford one right now. What might be my next best option?

I can't leave my Stanley range as it is, £300 a month on oil is too much. I am wondering if I have to bite the bullet and get a new oil combi and think about long-term when I have the money.

What is the best way to compare what my current stanley uses/costs when next to a potential new oil combi?

rosscouk

If I do decide to get a new oil boiler should i go system or combi? System is cheaper but I have to heat a hot water tank, so might heat more than I need. Whereas the combi you only heat what you use, but it is more expensive with more to go wrong. The system boilers are also slightly more efficient.

Which is a better bet?

Ben84

rosscouk wrote: »

Thanks Ben84, that makes sense. I would suspect I have 270mm but not checked. I need to do a little more research I think. I know I can definitely do more to insulate my loft hatch, its basically a sheet of plywood with no insulation on the back of it, this must be a bit of an oversight!

Loft hatches are an often overlooked source of heat loss. It should have draught strips to stop heated air rising out and insulation can help too. You can attach an insulating board to the back of the hatch door.

As for savings with a new boiler, the latest condensing boilers claim to be around 90% or more efficient, but these values are measured under certain conditions that may not be present in your house. Actual efficiency in use depends on a few factors, a major one being the size of your radiators as it affects how high you need to set the boiler thermostat for effective heating. However, the higher the water temperature is as it passes back through the boiler, the less readily heat transfers to it and so the lower the efficiency of the heating system at transferring heat to the house. Anyway, unless you have large modern radiators already or install some, I would not factor in getting the full efficiency % the boiler claims. Most existing radiator systems are not sized to run effectively at the lower temperatures which suit modern condensing boilers.

Still, this isn't to say condensing boilers don't help, if you have an old boiler that's probably somewhere in the 60-70% range, you can reasonably expect an improvement as condensing boilers should have a bigger heat exchanger and be more efficient, it's just unlikely they would run at the figures most manufacturers are quoting. If you install bigger radiators or underfloor heating, the quoted efficiencies are possible.

rosscouk

Thanks Ben84.

One of my questions to the plumbers I have coming around is in regard to the radiators. Most are double panel affairs that appear modern enough. I want to talk to the plumber about whether it is worth upgrading some as they look a few years past their best and possible about upsizing some.

I am leaning towards a combi boiler currently I think, due to practicalities. It terms of efficiency, I just hope it is better than the stanley at 110+ litres a week for not much use!!

Ben84

rosscouk wrote: »

Thanks Ben84.

One of my questions to the plumbers I have coming around is in regard to the radiators. Most are double panel affairs that appear modern enough. I want to talk to the plumber about whether it is worth upgrading some as they look a few years past their best and possible about upsizing some.

I am leaning towards a combi boiler currently I think, due to practicalities. It terms of efficiency, I just hope it is better than the stanley at 110+ litres a week for not much use!!

You may not need to increase their size when replacing them, modern radiators with the metal fins behind them of the same size emit a lot more heat than the typical old ones did. You can also get double radiators which emit even more without significantly increasing the space the radiators take up.

However, when mixing different radiators there is the possibility the heat output of the system will be unbalanced. So, I would always want a thermostatic valve on any radiators replaced to avoid overheating. To be fair, if you have a plumber out who is draining the system entirely it would probably not be too costly to have thermostatic valves installed all over the house at the same time. It was the best improvement we made to our central heating, we have a lot more control over each room now and aren't wasting gas overheating any of the rooms either.