20 year old boiler Vokera Linea 24 may have had its day.
We inherited the boiler when we moved in 16 years ago at that point the boiler was 6 years old. It’s had a few heat exchangers on the way.
For my sins we’ve always had a BG home care agreement.
Few weeks back water starts to fluctuate hot and cold resulting in boiler turning its self off. BG engineer has advised us that they don’t recommend fixing as the system is full of sludge, I know this is true as we’ve never done it so there must be 20 years of sludge. By the time we’ve paid to have system flush either with BG or independent will be £600 minimum and this doesn’t guarantee it’ll cure the problem.
Obviously the BG engineer is eager to recommend that BG quote for the job, like I didn’t see that coming ! The guy was a nice bloke overall.
Going to get some quote from recommendations and BG

4 Bedroom
9 radiators
1x bath
1x shower room

My estimation is between £2500-£3000.00 inc VAT
Independent will throw in London tax for good measure, though I’m pretty certain it’ll be a lot less than BG quote.

I’d be expecting the power flush included in this quote ! Or is that pushing it.

BG doesn’t have a great reputation which my in-laws unfortunately found out the hard way a good few years back along with the million complaints all over the web.

Have you or anyone you know ever had a good experience with British Gas ?
I like the false security they offer as they’re a huge company and I’d like to hope they’re not that bad should things not go to plan. But then again I would like to use an Independent, though these can come with horror stories.
I don’t have the time nor inclination to want to go sparring with an Independent if it goes wrong.

I welcome all thoughts and advice helpful or not.

As you say, the negative customer service reviews may mean that you’ll don’t get the backup you need, and you’ll be sparring with them instead if anything goes wrong. Plus they will likely massively overquote compared to an indy. No harm getting a quote though.

2500-3000 in London may be optimistic, especially if it’s not a like for like swap and you need a flush.

depends on the boiler you chose to a great extent. I paid over £3000 for just a boiler change and flush 5 years ago in Edinburgh

London / british gas / much bigger house than mine I would be expecting 6000. But choice of boiler can mean a big difference. cheap boiler under £1000 expensive one well over £2000

Vaillent boilers are really good and expensive

BG are known for quoting stupid money. However my brother did go with them as they were only £500 more than others

Second opinion on the fault might be a plan, but at 20+ years you’ll probably throw good money after bad and keep an inefficient boiler.
There are options on supplier/fitting that will be cheaper that I’d explore, but at this time of the year it might be worth a premium to know that it’s done before the inevitable faff of Christmas, public holidays, etc
You should be able to offset the cost of a year of BG Home Care against the boiler warranty and not needing a service for 12 months

If there’s no point fixing the boiler due to sludge…………… what is the sludge going to do to the new one. Sounds like a cop out to me. Speaking as someone having a new boiler fitted monday(£2800 in Sussex for 4 bed, 2 shower 13 rads.

My ex-colleagues partner worked for Centrica, their new boiler quote after employee discount was still more expensive than getting a local supplier. Whilst they’re replacing the boiler and a power flush get them to install a magnetic filter.

British Gas historically charge way too much for what they offer. We had a BG quote to replace an old back boilered open system to a new combi. BG’s quote was thousands of pounds more than 3 local fitter quotes we obtained. At that point we bought a Worcester Bosch and had it fitted by a local company. The WB boiler had a seven year guarantee provided we got it serviced by a WB approved engineer. After the seven year period we plumped for a BG service plan and guess what? That Christmas the boiler started leaking. Phoned BG and was told it would be a two week wait for an engineer. Luckily we found someone local who fixed the problem a lot quicker. Forward to last autumn, the boiler sprang a leak so another call to BG and told again it would be another 10 days until an engineer could attend. Anyway to cut to the chase I remembered watching adverts for BOXT boilers so looked them up. Seemed to good to be true, reasonable prices and quick delivery and install. I ordered a new WB boiler from them on a Sunday and it was fitted a few days later. 10 year guarantee. I’m factoring in probably having to change boilers every 10 years from now on. Oh and BOXT do a pay monthly service scheme which is very reasonable.

Surely the point of a maintenance contract is that when it breaks they come out and fix it.

I had mine replaced with BG 4 years ago for a few reasons. The price was not much more than other quotes, it was interest free over two years, it included boiler and all other plumbing related cover and annual service check.
I have used the cover a couple of times and they were very good so happy that I went with them.

I’ve never seen the value in these maintenance contracts. Mostly an annual tick the boxes safety check and if something does go wrong they call ‘sludge’ and wriggle out of any responsibility.
Not bitter honestly.

I paid £3500 in the spring for a new boiler to replace 40 year old one. £650 of that was flushing the system.

Gas usage has roughly halved since the switch.

Independent will throw in London tax for good measure, though I’m pretty certain it’ll be a lot less than BG quote.

I think your estimate will be the starting point for independent. I’m not London although it’s relatively affluent in St Andrews, and that’s ball-park what I’d be charging for Magnaclean and a new boiler assuming you didn’t want a no-frills one. In the region of £1500-2000 for a decent boiler and flue/filter/etc., £500+ for the powerflush, plus a day’s labour for the boiler itself assuming it’s an easy swap.

Get yourself here for a quote https://www.boxt.co.uk/

BG doesn’t have a great reputation which my in-laws unfortunately found out the hard way a good few years back along with the million complaints all over the web.

In defence of BG installation and service, they use contractors as well as staff engineers and like any big company the service you get can depend on who you get. My indy plumber (also a bike riding mate FWIW) contracts some days for them and I don’t think offers any lower service based on the polo shirt he’s wearing that day.

No, it’s the whole corporate set up at BG, not the engineers themselves.

I’m with them for utilities (until I switch, but can’t until they sort my meter saga) and it’s take 10 months so far to fit a smart meter – every appointment cancelled on the day – next available one is 2 months. Rinse and repeat.

I’d be nervous of a power flush to be honest, how old are the radiators and how solid are they? I’m in a 20 year old house and have replaced all the radiators as they started to fail after about 15 years. If you really want to clean the gunk out take off each radiator and flush it through. The flush the entire system by filling and draining.

I’d also replace a boiler of that age, it’ll be 30 year old technology with 22 years of performance degradation. I think a boiler replacement will be more than £3k, cost us over £2k 5 years ago and that was with my wife’s team of heating engineers doing it at cost when they were quiet.

Mine this year was £3.5k for Worcester Bosch boiler. Magnetic trap. App controlled thermostat. Plumbing to change from tank system to combi system.

Two guys working two long days to do it

Gas usage halved compared with old 40 year old boiler with poor controls.

Local company did it. Also had entertainment of another local company quoting £2k more for the same job with cheaper boiler.

I had used Boxt to get a starting point so there was no way the chancers were getting the job. Would have been roughly £3.5 labour for a 2 man 2 day job. And this is Glasgow area so no London tax.

I like the false security they offer as they’re a huge company and I’d like to hope they’re not that bad should things not go to plan.

They’re admistratively in a mess just now – migrating from one system to another and although some of their customers are on one system and some are on another the two systems can’t see each other.

I spent several hours yesterday being batted between their web chat and phone services just to give the closing meter reading on one property and the opening on another – both properties that they are the current supplier of but one one each side of this migration with differnent customer service teams.

The poor folk in charge of their ‘old’ system both know they are watching their jobs disappear – the point of the migration is to make customer services web/app only –  and having to deal with customers that are only furious because their website fails to articulate whats going on – it just doesnt work for anyone. I was managing to stay civil and once everything was finally resolved (I think) the poor wee lamb didn’t seem to want to end the call – I suppose she knew that as soon as I put phone down the next furious call would come through.

Or spend a tenner on some Sludge remover, and around £180 for a full power flush.
Then you should have a nice clean efficient working system
Even if it doesn’t work, you won’t have wasted your money as most boiler fitters make you have a power flush to get the warranty.
Also fit a mag trap atbthe same time and refill with inhibitors

around £180 for a full power flush.

Where’s that from? It’s 5-600 quid round here!

You can rent a powerflush machine for £80 from HSS if you fancy a bit of DIY

If pipework is copper and rads are aluminium(?) what are you trapping with a mag trap.
Bits from the heat exchanger?
Serious question.

We have a 40 year old Gloworm & rads so will be going through this soon, ish.

Most rads aren’t aluminium, they’re steel.
Thats what you are trapping with a mag trap.

Pretty sure there were recommendations for Heatable on here previously..

@singletrackmind
Cheers.
Didn’t know that.
Mine are, but I thought most were Al now.

Seek independent plumbing advice.

London? Is the system water softened before filling? That London water is fairly sludgy straight out of the tap, have it circulating at high temp and topped up now and again and it probably ends up near solid.

I’d expect that the filling tap would have a softener connected. But then I’m not a heating engineer.

A magnetic trap is only going to deal with the swarf and iron-based bits that would otherwise mess with the pump.

If you are replacing the system OP I’d at least double that estimate. Last year it was about £3,500 for a Viessmann boiler and gubbins just before Christmas. In the north of England.

If you go down the replacement route BG will likely fit a Bosch boiler.

Don’t get one of those with its cheap, leaky aluminium heat exchanger. Get a Vaillant or Viessmann: something with steel innards.

Consider an ASHP? It won’t deal with your sludge problem but no burning gas at home. Viessmann now do ones that will pump out water at 70 Celsius.

@dantsw13 are you aware that if your utility company misses an appt you are entitled to something like £35 off them? Not sure if it covers same day changes or not, but worth a check

what are you trapping with a mag trap

The rad, whether aluminium or steel, tends to corrode before the copper pipes partly because the rad reacts with the copper. Inhibitors and a mag filter help where steel rads are fitted and reduce deposits around the system. I assume plastic pipes are an advantage but I don’t know how this works in practice

Prettygreen – not sure any modern boiler has a steel heat exchanger, stainless steel is more likely, I think most companies use a stainless / aluminium combination.

Steel would contribute to the problem too, and don’t use a heat pump and run it at 70 flow temp, it will be very expensive to run and not what it is designed for.

If you are serious about sludge then look at VDI 2035 which is from Germany. I have first hand experience of Elysators and I have never seen cleaner heating water than the sample I took from a 6 month old system, compared to the sample at the start. I have photos somewhere if anyone is interested.

Oh and don’t use softened water as it will invalidate some manufacturers warranties

Thanks for all answers

Has anyone used BOXT or Heatable ?

Both the quotes from them seem okay.

Just fitted a new one (live in Tooting, London). I purchased a 28 kwh Vaillant Eco Tec Pro, the boiler was £1,200 from Plumb nation (delivered within 3 days), needed a new Thermostat (£160). I paid a registered Vaillant fitter £800 to install, took around 6hrs, chemical flush included in the price, most systems are fine with a chemical flush as you are running water through the system with the drainage valve open, this flushes the old crud out. I also added a Magnatec Filter (£150), so it can be done for around £2300ish. I had a few quotes that were on the high side.

I got a new boiler last year, I’m in the trade so I know gas safe fitters…so I get mates rates, but BoxT boilers from the telly are really good value and only about £200 more than what my mate charged…..

Why are they so expensive?

Serious question, I have no idea. They make water hot. If you spent three grand on a fridge or a tumble dryer people would think you’d lost your mind. And £500 to stick a hose on one end and a bucket on the other?

Presumably all of this is a lot more complicated than I’m giving credit for.

We used Boxt a few years ago.
Just before Xmas and when everyone else was quoting 3/4 weeks and silly money Boxt were literally there the next day.
New boiler, including upgrading diameter of pipe back to the meter, all done in less than a day for at least £1K cheaper than BG.
This was a few years ago and they were very new on the scene then.
Rumour was that it was two guys in the supply chain related to Worcester Bosch, buying up on a huge scale and then paying good money to installers to travel up and down the country.
Suspect it may be more of a level playing field now, but it was all pretty exceptional when we did it. Was just waiting for a catch the whole time, but it never came.

Spent time on both Heatable and BOXT
Both are similar prices £2500.00

This included
Viesmann https://www.viessmann.co.uk/en/products/gas/vitodens-050-w.html

Or

Worcester Bosch greenstar 4000
https://www.screwfix.com/p/worcester-bosch-greenstar-4000-gas-combi-boiler/459pr

Also included is
Power flush
Flue
Filter

Both come with 10 year warranty

all fitting allowing for gas pipe replacement to boiler if needed
Not interested in being able to control from phone.

I can’t deal with tradesman trying it on and giving me BS. can’t imagine an independent would come near that price though I think the fitters for both BOXT and Heatable are self employed.

*have a few recommendations for independents and will give them a ring tomorrow.

What could possibly go wrong !

Powerflush alone is around £500…takes ages

Your system may not need power flushing, chemical flushing (running the system for 20mins with additive to break down the iron oxide build up) should suffice. When you chemical flush the system you open the flow/return value and are flushing with mains water pressure (roughly double the pressure of the system), this will blast out most gunk, the remainder will be picked up by a magnetic filter on the return flow pipe.

Why are they so expensive?

They aren’t really, you can pick up a new Vaillant/Bosch for around £1,100 to £1,300, there is a lot of technology in them, a fair bit of Copper and Aluminium and a limited supply market. Cheaper makes could be purchased around the £900 mark. I would not go near the big gas companies installing… British Gas are just a gas supplier, your warranty is with Vaillant/Bosch etc. Check Plumb Nation, they don’t always have good delivery times, but you can buy a boiler there cheaper than most plumbers could.

We had the Greenstar 4000 fitted this year by an independent Bosch accredited company. £3500. But that also included plumbing work converting from tanked system to combi. Removing loft tank and rerouting all hot the water feeds in the house so they run from the boiler rather than tank etc. New flue, filter, etc. Chemical flush.

Very quiet compared to our old boiler. So far uses half the gas for hot water. Still waiting to see a cold month usage but signs are good. Gas usage October this year was approx half last October.

We have a desktop thermostat in the lounge which is connected to the boiler via wifi. Also a phone app. The phone app is worthwhile. As well as allowing control from anywhere is gives easy access to setting timer programs. Also show gas use in KwH per month split into gas and heating.