Bit worried our boiler (Potterton Netaheat I think) may blow up. We have had it the 20 years we have lived here, not sure how old it was when we moved in

I believe it is around ‘70% efficient’ – if a modern boiler is say 90% efficient, would you save 20% on your bills? Anyone got any experience of pvings in potential savings in running costs? our bills are pretty high

can’t decide whether to change it or wait for it to fail – which would probably be in the middle of winter….

thanks

Our plumber (who was a friend so not out to con us) said we should keep our old boiler going as long as possible. Unlikely to make the money back in savings and modern ones tend to be less reliable so potential extra expense

Note that the boiler is just part of the heating system, the pipes can lose heat, radiators, controls, hot water system, etc, so the 70%-90% is not a direct figure, but if the boiler is nearly at the end of life (i’m in a similar position) keep it serviced and ask about spares, if it gets too old for spares that’s the time, hence asking engineer about servicing, spares etc.
Worth getting some quotes for a replacement so you are ready and speaking with local plumber or whoever services your currently.

Is it a Combi boiler ?

If you can do things that help save money and make things more convenient then worth doing.

But just changing for sake of it not worth it IMO.

When things start to go wrong I would get rid

20 years ago we swapped a really old back boiler for a modern (at the time) combi boiler. The gas savings were 30% +.
Partly due to better controls, and not heating up a large tank of water all the time.

Research here http://www.miketheboilerman.com/

its likely that as your boiler is properly old its worth investing in.

This is a link from his website http://www.netaheat-repairs.co.uk/

So 20% savings, annual gas bill of £1000 then you’ll save £200.
New boiler install £2000, then 10 year payback, assuming no maintenance other than annual service.
Pretty simple boiler the Netaheat and pretty certain spares are still about. Considering the number there were installed I seem to repair very few.
However it is coming to the end of its life realistically so time to budget and plan. Hopefully that will mean you won’t have to rush into it and can pick a good installer.

Arghh. Our 37 year old Netaheat 16-22 failed on Saturday just before xmas (the 22nd).

Heat exchanger sprung a leak and water, water everywhere. Isolated it, power and water (tied up the ball cock in the header tank), also had to drain down the upstairs radiators.

British Gas had a look, no spares.

So fan heaters and oil filled radiator and emmersion heater kept us going until plumbers merchants were open.

We knew it was on borrowed time, and had planned to replace this summer, but it got us in the middle of winter….luckily over xmas it was mild.

So, now the boiler is changed (Worcester – Bosch 18kW). I also replace the copper water tank for a stainless steel one and re-jigged the valves from 3 port Y to 2 S valves (1 hot water, 1 for heating).

So the point of my ramble, I am expecting savings, the boiler is firing up less often, previously the thermostat was at 20, and often turned up above this (probably to heat up the limescale in the tank) Now thermostat is at 18, we have not adjusted it since 9th Jan and there is loads of hot water for showers.

Cost me a bit, and a bit of time, but money well spent – no complaints from the noshers.

We had a 20+ year old combi replaced in November with a Worcester 30i.

It is much better. House is warmer, water is hotter, it uses noticeably less gas.

I’m expecting maybe 25 percent cheaper to run for a better performance.

We are on lpg.

I know it sounds gimmicky but maybe think about one of the newfangled “smart” thermostats. We’ve got a reasonably new Combi boiler but in a very old and leaky house. We were using roughly 3500 kWh of gas a month with a simple on/off thermostat. I swapped that for a Nest and wired it up to use OpenTherm (I concede that a 20+ year old Potterton probably doesn’t speak OpenTherm) and we’re now using 2800-2900 kWh a month. Same temperature on the thermostat, just a more efficient use of the boiler.

£165 for a thermostat (or ~£250 to get it fitted by someone) vs £2000-ish for a new boiler? Got to be worth a shot, even if it only saves you £10/month it’ll pay for itself well before a new boiler would.

I agree with the smart star advice. Not sure how much difference it makes when it’s running buts ours is great at turning the heating off when we’re out.

During full house refurb 2 years ago I swapped a 15 year old baxi combi for a viesman combi, the baxi had been brilliant at actually throwing out heat and hot water but in its time it had 3 pumps 2 pcb and an expansion vessel fitted to the side as it’s internal one was ****. The savings are noticeable in gas, it runs on a remote stat and has a free 7 year warranty if serviced regularly by a viesman approved installer and also came with a full magna clean system. I’m also saving the 18 quid a month that I was paying in boiler cover. As I know a few folk in the trade and deal with a lot of merchants it was purchased by me and fitted for about 1400 quid so a no brainer.

believe it is around ‘70% efficient’ – if a modern boiler is say 90% efficient, would you save 20% on your bills?

No. Your bills include significant standing charges, your hot water won’t be much cheaper, plus do you cook on gas?

As a rough guide, subtract a summer bill from a winter bill, then take 20% of the remainder.

Assuming insulation is up to spec, a foot of loft insulation etc, you will see a saving but it depends on how you use the heating. Off completely is ok but if it then takes 2 hours at full blast to get it back up. Would you be better trying a timed stat that drops it by a couple of degrees during the day/overnight?. I noticed no real change in bills doing this…

Midlands, new build 4 bed detached, wife who ramps temp up whenever she can, using about £35 a month of gas over the winter months. Old house, ex council semi, was closer to £50-£60 over winter months.

I also spend a lot of time researching the best energy deals on u switch and money supermarket, I’m not put off like many on here by the big companies either, tsall about the kwh and as above daily standing charge for me, that’s why I’m with Scottish power until April. Plus, having a hot tub sharpens your deal sourcing skills!!!

Our new boiler saved about 10-15% over the two years fitted compared to the old, old boiler before.
I saved a bit more this year because we fitted an external temperature sensor. It noticeably more responsive to outdoor temps – firing up early to warm the house or late if not needed.
I’ve also been updating the radiators and TRB’s one by one.
Biggest thing is that the house is more evenly warm.

Thanks – all very useful

House is > 500 years old, brick on mud floors, insulated mainly of poo and horse hair! So our bills are quite a lot more than people are talking about here….

Using ransos’ Formula we’d save £30 / £40 a month

maybe a silly question, but is there a smart thermostat that doesn’t involve a subscription?

Del, I have a Worcester Bosch smart thermostat, no subscription.

Nest, Honeywell Lyric, and think the Drayton Wiser too.

I have a netatmo account for remote access etc but no charges.

maybe a silly question, but is there a smart thermostat that doesn’t involve a subscription?

All the others that you haven’t looked at yet (Evohome in my case). Actually, I’m curious to know which one is subscription only?? I was aware that Tado do a rental option, but you can also buy the kit outright if you wish.

Sorry – i did say it may be a silly question! i thought they were on a subscription model. i think i got that impression from my neighbour who has one, but to be fair, she’s mad as a box of frogs so i probably got the wrong end of the stick, and i just haven’t looked in to it. but thanks for the responses – you’ve disabused me of my notions and encouraged me to look in to them more. 🙂

70->90% means you will use (70/90) ie 78% of the gas you previously did, in theory.

I also spend a lot of time researching the best energy deals on u switch and money supermarket

Commercial comparison sites don’t show the whole market.

CAB and I think Which show cheaper suppliers, I often find deals £100s cheaper there than uSwitch (I advise on this stuff as part of my work).

Bit worried our boiler (Potterton Netaheat I think) may blow up. We have had it the 20 years we have lived here, not sure how old it was when we moved in

We have a Potterton Netaheat, I’ve been keeping it going myself for the last 20 years. It’s probably 30 years old now. Can’t see any reason to change, you can (or at least could) get all the spare parts except for the gas solenoid valve (might be able to get one from a scrap merchant). Supposedly was 77% efficient new. Every time I’ve done the maths of a new boiler payback was 15 years ish, so didn’t make any sense.

https://www.diynot.com/diy/threads/effficency-rating-of-an-old-potterton-netaheat-10-16-boiler.37522/

That thread reminds me, ours needs de-scaling again…

70->90% means you will use (70/90) ie 78% of the gas you previously did, in theory.

You get a lower efficiency for hot water and need to allow for gas cooking, if applicable.

I was aware that Tado do a rental option, but you can also buy the kit outright if you wish.

Tado recently changed their product so that if you want a few things like automatically changing the setting when you’re in or out you have to pay a monthly subscription. This was previously their main selling point. This seems crazy to me, but hey ho…

British Gas had a look, no spares.

You do know their service guys are on commission to sell new boilers. Notorious for saying no spares when they are readily available. Although to be fair in the case of the Netaheat, you’ve had a good run from it, so I wouldn’t be too bothered.

NB Just had a quick google and you can buy reconditioned heat exchangers.

In the case of older boilers the original part might not be available eg the pressure switch went in ours, but I just bought an OEM for £15 and some new tubing and fixed it.

Never ever ever trust a British Gas engineer telling you they can’t repair your boiler.