Oil combi installation

MK124RED

Hi everyone, hoping you can help me here.
We are renovating an old property, and for various reasons the heating is limited to the current storage heaters (don’t get on with them, they have to go), or an oil system. Heat pump isn’t possible due to the poor insulation and too much money to bring up to a level required. I would consider LPG but nowhere sensible to have the bulk tank.
I’ve received a quote from a heating engineer for an oil system. This includes the storage tank (1000L) and construction of the base, as well as connecting to the external combi boiler (Worcester 12/18). It’s just shy of £9k. Seems a lot! Or isn’t it? I’m wondering how much of it I can do myself to save some money. Thanks. 

QrizB

£9k seems pretty cheap for an entire new oil-fired system where there's no existing wet central heating.

MK124RED said:

Heat pump isn’t possible due to the poor insulation and too much money to bring up to a level required.

However much heat your property needs, you can get it from a heat pump. Insulation will reduce the heat demand and save money but that's just as true with an oil system.
Have you asked anyone for a heat pump quote? It might be cheaper (after the grant) than the oil system.

You can get an indicative quote from Octopus in minutes:

https://octopus.energy/order/heat-pump/

MK124RED

Thanks for your reply. I should have said that £9k doesn’t include the pipes and radiators. I’ve looked at octopus and their online quote comes in far cheaper at just over £4.5k, including radiators. I just can’t see it working well in this house, old double glazing, empty cavity walls. Surely it’ll cost a fortune to run to keep up with the heat loss?

QrizB

I don't know what the heating demand of your house is, butlets assume it's 20,000kWh a year (roughly doubled the average house).

Oil is about 6p/kWh at the moment. Electricity is about 24p/kWh, but a heat pump should give you at least 3kWh of heat for each kWh of electricity, making the heating 8p/kWh..

20000 kWh of heat from oil will cost £1200.

20000 kWh of heat from electricity will cost £1600.

That's more, granted, but if you're saving at least £4.5k (probably more like £9k, if you include plumbing) it'll take a lot of years of £400 extra on your energy bills before you're any worse off. And that's ignoring the finance costs (or loss of investment) on the £4.5-to-£9k that you haven't spent.

tacpot12

You might be able to save money on the oil tank installation by doing it yourself, but there are some bits you can't do yourself. You need an OFTEC approved engineer to do an oil storage risk assessment. If you get them to tell you want you need by way of a tank and give you a design for how the tank needs to be installed, youmight be able to build the base and any bunding needed yourself. My suspicion is that you won't save much money. 

A heat pump is a big risk, but you might find that it works for you. You should fully investigate the true costs of oil-fired heating and compare these to a heat pump quote, based on the heat loss from your home. You need to get the installer to give you their best guess at what your SCOP will be. Check that a heat pump still makes sense if the SCOP is 0.5 lower than their best guess. 

Unfilled cavity walls are not the end of the world, but combine this with old double glazing and minimimal loft insulation and you have a recipie for high heat loss which will cost a lot in oil/electricity. 

FreeBear

QrizB said:

MK124RED said:

Heat pump isn’t possible due to the poor insulation and too much money to bring up to a level required.

However much heat your property needs, you can get it from a heat pump. Insulation will reduce the heat demand and save money but that's just as true with an oil system.

The National Trust have been installing heat pumps in a couple (may be more) of their properties. Admittedly, these are big commercial systems, but even so, running costs have been lower than the oil fired boilers they had been using.

Historic England have published a report* on 10 small scale domestic installations. Most of the properties did not have the benefit of massive insulation upgrades, but the conclusion was that heat pumps were effective. Some were let down by poor installation and/or configuration which impacted on running costs. With a bit of fine tuning, there is no reason that most would be as cheap to run as oil or even gas. The key is to have the system properly designed (preferably with a flow temperature of 35°C) and an appropriately sized heat pump.

Octopus now do two types of installation - A Turbo with a design flow temperature of 50°C, or an Eco which uses a lower flow temp. The latter comes with a higher installation cost, but makes up for it with a lower energy usage.

*) https://historicengland.org.uk/images-books/publications/air-source-heat-pumps-historic-buildings/

MK124RED

Thanks everyone. Ultimately, a heating engineer and plumber who both work with heat pumps have told us that our house just isn’t suitable for a heat pump. I think for simplicity, we’re going to have to go with oil. So does £9k sound fair for the tank plus boiler installation? Pipework and radiators to be done separately. Thank you all for your help. 

lohr500

Edited to correct date of our tank replacement.

£9k does sound a little on the high side.

In 2020 due to storm damage we had to have our 2500 litre tank replaced.
That involved pumping out +/- 2000 litres of oil from the damaged tank into temporary storage tanks, removing the old tank, enlarging the existing concrete base, installing a new double skinned 2500 litre tank and transferring the oil back out of the temporary storage tanks.

Total cost £2400.

It would take a little longer to create a whole new base, rather than extending an original base, and there would be work to run the oil pipe from the tank to the boiler location, but unless the location of tank and boiler were complicated those costs shouldn't be massive. And you don't have the old tank and oil transfer to worry about.


In 2021 we had our old oil boiler replaced with a modern condensing boiler. Total cost £5100.

That cost included two days work to reconfigure the existing hot water and central heating pipework to a new "S" plan system with two motorised valves and extra pipework to allow us to locate the new boiler outside, freeing up space in the kitchen. And changing one interior radiator for a higher output version.

Our new Grant boiler (with 10 year parts and labour guarantee)  was a 36kW conventional boiler which cost +/- £3500 at the time. A new Worcester 12/18 external combi is now around £3600 so a comparable cost.

Given your quote doesn't include any plumbing work or the removal of an existing boiler and changing a radiator, then it shouldn't be as expensive as our £5100 cost.

My gut feel says you should be paying around £7k tops, but purely a guess without understanding the location, availability of good quality approved installers, etc.

I looked at heat pumps before getting our old oil boiler replaced, but the challenges of improving the insulation in our 18th/19th century converted farmhouse, with rubble filled sandstone walls and stone floors was not to be underestimated. Two different heat pump "specialist" companies quoted for ASHP and both concluded we would need the electricity supply upgrading to three phase and would need two high output heat pumps working in parallel to achieve the required heat. And virtually every radiator in the house changing. ASHP technology may have moved on though in the past five years. I don't regret sticking with oil.
That being said if your installation engineer has done a good job of sizing the boiler requirement and has concluded a 12/18 combi will be big enough, then any heat pump alternative will be on a smaller scale than would have been needed for our property.

You also have the benefit of installing the radiators and pipework from scratch, so they can be sized appropriately from day 1.  In fact, if you decide to go with oil, get the radiators sized to support a heat pump anyway, Not only does this future proof the installation, but it will allow you to run the oil boiler at a lower flow/return temperature which will help it run more efficiently. 

Rodders53

1000 litre tank is small.
Probably too small if your home will use the 20MWh of energy to heat it guesstimated above. 
That'd be 2000 litres per annum... and 3 fills probably, as you won't be wanting to go too low (in winter especially). 

Your EPC might give a better guess at actual energy needed.

Your technicians are going the lazy and most profitable route imho in avoiding the work needed in fully calculating the heat pump design for room by room heat loss.  Spending money on improving insulation and draught-proofing would be worth it regardless of using oil or electric and should be done regardless.

Note that 2021 vs 2025 prices will be higher as will the cost for the tank.  Our replacement 1225 litre bunded tank cost over £3k in 2017. 

NB1 no VAT on a heat pump install, unlike oil.

NB2 Avoid combi oil burners.... They are not the same as combi gas.  They store hot water internally.  Get a proper system version and a good unvented hot water tank.

spannerzone

I'd get a 1200litre tank as miniumum. I'd personally avoid a Grant 26e combi boiler if that's still being offered, I have one and it's so unreliable despite Grant having an excellent name (I think based on their older designs). I don't really have an issue with combi boiler except that as it's an outdoor model, it takes 15 seconds of running the hot top before you get hot water as it comes from a fair distance from the house......however I wouldn't want an oil boiler indoors are they always seem to smell of oil.

suffolkphotog

I would agree it seems a bit high is that inc VAT

out new external oil boiler was just under 4k 18 months ago around 1500 for the tank and associated bits. All inc var.

Minimum oil take Mauser would be 1250 if you have space for bigger then do it. Minimum oil delivery is usually 500l and the price vary’s massively from winter to summer also based circumstances. In 16 years we have paid as little as 19p (covid) and as much as 90p (some random oil crisis) but usually floats between 35-40 in summer and 55-75 in winter. So a big tank you can fill in summer for the year is worth the money. 

We also collectively buy as a group of houses which gets 2-5p a litre off the price, a bit more if you can get to around 12k litres as that’s a tank full.

i would check on the heat pump with a specialist we got the same info. It wouldn’t work. House is too old, but someone has done it on a similar house to ours (extended 1820 cottage) and they have got it to work. With much lower bills

We can’t get a smart meter (no phone signal) and can’t have solar (conservation area)