Switching from oil to gas heating

Samantha_Marie90

Hi all,

I'm a first time house buyer and have recently had an offer accepted which is exciting! It's going to be a bit of a renovation project and I need some help with heating. The house is currently using oil and I'd like to change to gas.

The estate agent has told me that there is gas already on the estate so it seems like this switch should be doable. But, what it comes down to is the cost (as always). I realise gas probably is more expensive than oil in the long run but I want more efficiency which I think is where gas works better and also to add value to the home.

Any help greatly appreciated!

CliveOfIndia

OK, the first thing is to find out how much it'll cost to get a gas supply connected up to your house.  Yes, gas may be available on the estate, but if you haven't actually got a gas pipe running to your house then it can be surprisingly expensive to get one installed.

Secondly, you'll need to factor in the cost of a new boiler.

There's very little difference in the running costs between gas and oil, so it's going to take a pretty long period of time to recoup the initial outlay.

Now, if the existing boiler is old and very inefficient, and you're going to replace it anyway, then the biggest factor is going to be the cost of getting a gas supply installed.  If that turns out not to be too expensive, then there may be an argument for switching to gas if you want to.

Oil does have the advantage that you can shop around for the best price very easily every time you need to buy.  And you can, to some extent (depends largely on the size of your tank) buy when the prevailing price is cheaper.

Don't forget you'll be paying a standing charge for gas, which you don't pay for oil.  Although, it's sensible to remember that at some point your tank will need replacing, so you could argue that that's kind of a "standing charge", if you want to look at it that way.  What's the average life-span for a plastic tank - something like 15-20 years I think?  So that's a lot of "daily standing charges" you could be putting away for when you do eventually need to replace it.

I'm not sure how much extra value a gas system would actually add to the house - there's nothing intrinsically wrong with oil.  When we moved into our current house 16 years ago, that was the first time I'd ever experienced oil heating.  I didn't have a clue about how it all worked, but I very quickly came to really like it.  I reckon overall it's very marginally cheaper than gas, just based on how much we used to pay in Direct Debit every month for gas compared to how much we were spending on oil.  Although that was only a valid comparison for the first couple of years, I guess, I've no idea what I'd be spending on gas these days.

Finally, there's the argument about going down the heat-pump route.  I can't really advise on that as it's not something I know anything about, but they do say that's the way forward.  Personally I'm still sceptical that they can work very well in the typical Scottish climate, but that's a whole different argument.  Plus you've got the added expense of probably having to replace the radiators as well.

Anyway, my thoughts for what they're worth.  On a purely "running costs" basis I don't think there's much - if anything - in it.  It's the upfront costs that may sway it for you.

Veteransaver

We were in similar situation when we bought our house years ago, but the sums never really added up for going to gas. Gas should be slightly cheaper on average but when you factor in standing charges etc there isn't a lot in it. Oil price is very volatile though. Eg start of pandemic it was ridiculously cheap as there was such a glut of fuel.
We now have an external oil boiler (you can't really have an external gas boiler) donthat freed up some space too.
Oil boilers are a bit more expensive to buy, though they are supposed to last a lot longer.

Rodders53

Never trust an Estate Agent.
Do your own due diligence.  Find out if there is real mains gas running past this house... 
You may not wish to find out that the 'gas on estate' is piped from bulk LPG storage tanks (as they are on two estates near my home). 

Modern Oil boilers are condensing and can be pretty efficient, probably equally as efficient as gas.  Where gas boilers can win out is in being able to modulate down the output range so burn longer rather than cycle on/off when radiator TRVs close down.

Air to Water Heat Pumps may be worth investigating if/when the oil tank and/or the boiler are due for replacement.

FreeBear

CliveOfIndia said: Now, if the existing boiler is old and very inefficient, and you're going to replace it anyway, then the biggest factor is going to be the cost of getting a gas supply installed.  If that turns out not to be too expensive, then there may be an argument for switching to gas if you want to.

Been doing some "what if" calculations here. Currently have a combi gas boiler (installed last year), and had a quote from Octopus last week for a heat pump. Taking in to account purchasing a [redacted] load of copper pipe, fittings, and radiators, replumbing the whole system, and paying a Gas Safe engineer to install the boiler, it cost me around £3,000.

Octopus are quoting me £2700 for a heat pump which includes new radiators, hot water tank, and a minimal amount of plumbing. Could probably drive that price down a bit.... But at that price, I would have had second thoughts about gas and seriously considered a heat pump.

Yes, electricity to 4 times the price of gas, but some heat pumps are returning a COP of 4 or even 5 (1kW electricity in, 4kW or even 5kW heat out). Certainly something for the OP to think about.

lohr500

Do you know the model of the oil boiler and how old the boiler and tank are?

If the boiler is relatively new and of a condensing design and the tank is in good order, then I would stick with it for now.

In broad terms, at current prices, oil and gas work out at about the same cost per kW/h if you assume both boiler types are of the same design. (ie both condensing or both non-condensing).
If you take the oil price per litre and divide by 10.35 this will give you the cost per kW/h.
When comparing oil and gas prices make sure you are looking at like for like with the VAT either included or not.
Also remember that boilers are not 100% efficient, so 1kW/h of fuel will not convert to 1kW/h of usable energy being supplied from the boiler into the heating system. That being said a modern oil boiler should be in the same efficiency band as a modern gas boiler.

I would only look to swap out the oil boiler now if it is a very old non condensing inefficient design. Otherwise I would stick with it until the time comes to replace it.

In my opinion when it comes to boiler replacement, the old saying "If it ain't broke, don't fix it" is spot on!

In due course you could look at getting a price for having gas installed to the property and also consider an air to water heat pump as mentioned above. The current grant of £7500 towards installing a heat pump may not be around forever, so it is worthy of consideration if the existing boiler is an antique oil guzzler.