Reducing oil use - under sink water heater??

[Twoshoesnewshoes]

We have oil fired central heating and water.
im wondering about getting an electric shower for the summer months so we can switch off the boiler.
ive just discovered under sink electric water heaters which might be good for the kitchen sink. I don’t know about them - anyone have any info or experience?
thank you!

Should add, we are not on mains gas.

I don't think it would work for me, no hot water in bathroom sinks etc? Would probably be more expensive than just running the boiler on hot water only setting. Seems like a step backwards to the 50's if I'm honest.

I do this. Tbh I didn’t bother with a fancy hot water tap as it would negate savings for years. Our pipes seem long so you never really get hot water for ages by which point you’ve finished your hsnfs. Also the water doesn’t feel that cold in summer

I've been wondering the same thing - the only worry I have is that the boiler won't restart in autumn (or actually, more that the hot water tank - already on its last legs - will die if it's not in constant use).

My friend swears by hers - but she's also got a back boiler on her living room stove, so she can also heat water/house with that if there's an issue with the oil.

My plan is actually to go the whole hog, and move to a heat pump and dump the oil boiler entirely (depending on advice, may or may not keep it as a backup - I'm also considering that if I really wanted to splash out, that replacing my electric stove with something like a wood-burning Aga could potentially cover the same bases as the oil boiler - albeit with some pluming shenanigans - but at least ones that are closer to where the water is used, rather than 30m away in the garage)

The boiler does traditionally have some kind of issue early January (or if it's very upset with us, the week between Christmas and new years), so I was thinking of just installing one of those under-sink water heaters just for that emergency.

Yes my boiler likes to strike, usually in v cold weather. I hadn’t thought about it as a back up but it would be useful.
some people in my area have a wood burner with a back boiler and it works really well.
I’ve been put off a heat pump by friends experiencing v high electricity bills.
we are probably going to move in the next couple of years so I don’t want to invest too much in this house - but feeling v guilty about the oil I am burning.

The maths don't work, but it depends on how old and/or efficient your boiler is.

Ours is about 10 years old in a new house with good insulation. We use 2.5 litres a day in summer for hot water. That currently equates to £1.35 at the current summer oil rate of just under 60p a litre. That gives us enough HW for a full bath, a ten minute shower with one of those massive shower heads that use a ton of water, and about two or three Belfast sinks of washing up every day. It comes on two hours in the morning and one in the afternoon.

When in a different house last year the poxy electric shower we had was costing 50p for about 15 minutes, and we still had to heat the water for washing up.

I don't think electric is ever cost effective these days.

I have one but I am all electric so it's my only source of hot water.
It's a 15 litre tank and fits into the dead corner of the undersink cupboard so isn't really taking up any useful space.
It was recommended by my plumber a decade ago when I needed the hot water tank moved as it was ancient, leaking and in a stupid place. He pointed out I only have an electric shower and cold fill dishwasher and washing machine (pretty much all are now) so what did I need a massive tank for.
It's connected to the pipework that feeds all my sinks so hot water in bathroom too

It is very efficient and works well. If I'm washing big trays or bits after say a roast dinner it occasionally runs out of hot water but it only takes about 15 minutes to heat up again so by the time I've wiped the surfaces and cleared the table it's ready.

My total energy use averages 10kwh a day so it's not drawing a big power load.

It's a 15 litre tank and fits into the dead corner of the undersink cupboard so isn't really taking up any useful space.

I'm not convinced by the tank ones - and bear with me here - I once had a water dispenser, which you could also set to dispense hot water, and it had a little internal tank - only a litre - and it absolutely HAMMERED my electricity bills. I'd go for an instant heat - but then, as I say, for me it would be a backup.

I think heatpumps hugely depend on the installer/house - my dad did his own, and it's been fantastic for him - house is the right temperature year round, and in summer he feeds back to the grid.

I think if you're not staying long, then your money would be better spent on efficiency upgrades to help the sale of the house, and so also reduce your oil usage. I think that when it comes to it, there's a lot to be said for the directness of 'burn oil, heat water' vs. 'make electricity from something, heat wire with electricity, heat water) - especially out in the sticks, where keeping it simple is important.

Electric water heaters for sinks/electric showers are electricity hogs and will cost you far more than oil heating. (Even though heating oil has quadrupled in price.) They’d be worth doing if you had solar panels and used them when the sun is shining.

Might make more sense to convert your oil fired boiler to run on biofuel

What’s on this page?

• 01 What is a biofuel boiler?
• 02 How eco friendly are biofuel boilers?
• 03 Are biofuel oil boilers currently available?
• 04 How much do biofuel oil boilers cost?
• 05 Where does biofuel come from?
• 06 Should you get a biofuel boiler?

What is a biofuel boiler?Biofuel boilers work in pretty much the same way as a conventional oil boiler, except they run on an eco-friendly substance.
Rather than relying on fossil fuels to heat homes, these boilers use biofuels, which is a type of fuel made from plants, as well as waste cooking oils, vegetable oils, and animal fats.
The most common type of biofuel for home heating is hydrotreated vegetable oil (HVO), which is a synthetic paraffinic diesel – sometimes also called ‘green diesel’.
This type of fuel comes with a plethora of benefits – it has low emissions, is cost effective, and has a storage life of up to 10 years (compared to one year for regular diesel).
If you're looking for a new boiler, our guide on what a new boiler might cost youhas all the information you'll need on pricing.

Can you convert your current oil boiler into a biofuel one?Yes, you can convert your oil boiler into a biofuel machine – and why not? You’ll save a tonne of money by not having to install a whole new heating system, which will also help you reduce material waste.
Although converting your oil boiler into a biofuel unit sounds complicated, it’s just a matter of replacing a few key parts. The most important part you’ll need to replace is the burner, since oil and biofuel burn at different temperatures. Doing this will also make sure your biofuel boiler performs at the best possible efficiency.
Biofuel is typically more corrosive than standard heating oil, which means it’s also standard procedure to replace any old seals for biofuel-friendly ones.

How eco friendly are biofuel boilers?Biofuel boilers are very environmentally friendly – especially when they’re compared to their oil counterpart.
The average UK home using an oil boiler produces 5.3 tonnes of carbon per year, but the UK and Ireland Fuel Distributors Association (UKIFDA) suggests that by swapping to an HVO-powered system, these homeowners can reduce their CO2 emissions by 88%.
For context, if all 1.5 million households that currently rely on oil switched to HVO, their collective emissions would drop from 10 million tonnes per year to 1.17 million tonnes.
But how do biofuel emissions compare to other types of fuels? Below, we’ve listed the most common fuels used to heat UK homes, and outlined how many kilograms of CO2e (carbon dioxide equivalent) each one emits per kilowatt hour (kWh).
Fuel type Emissions kg CO2e per kWh
Coal 0.395
Oil 0.298
LPG 0.241
Natural gas 0.210
Wood pellets (bulk supply for main heating) 0.053
Biofuel (from any biomass source) 0.038
Wood logs 0.028
Wood chips 0.023
Biofuel (from vegetable oil only) 0.018
Data from The Government’s Standard Assessment Procedure for Energy Rating of Dwellings
As you can see, biofuel made from vegetable oil (HVO) is much more eco-friendly than other mainstream heating methods.
However, it’s also important to bear in mind that biofuel carbon emissions depend on a number of factors, including its cultivation, harvesting, processing, and how far it’s then transported.
The chart below outlines where the UK currently gets its feedstocks to create biofuel. As you can see, the majority of it comes from other countries – namely China – which suggests that biofuel might not be as eco-friendly as it appears.

@SwitchDiver thank you,- I’ve been following Future Ready Fuel with interest Here is the website
but it looks like it’s not ready for rollout yet? I’m really hopeful that it will be a viable solution soon as it would mean minimal adaptation to an oil system.
the electric ideas are not for cost cutting- I know it will cost more. I’m looking to cut carbon emissions.

Oil is pretty cheap ATM, it never hit the giddy heights we got to in 2014 anyway, and is considerably cheaper than post-pandemic.

My suggestion is look at solar PV to heat your water. We have an older solar installation & a gadget that when we generat 0.2kw above what we''re using it automatically heats the hot water. As a consequence we don't run the oil in summer, only winter.
We also have a log burner with the capacity to heat water but nothing is connected to it, I'm thinking of modifying that so it can heat water in winter