Old Gas Boiler replacement - STILL not viable?

fuzileer

With gas prices well on their way to trebling if seemed the right time to replace my reliable 35-year-old G-rated boiler. The recommended new boiler is up to £1200 incl VAT, and online sources suggest an experienced gas fitter in the South East should be £380 a day, for the two days required to change my conventional floor boiler for a new wall mounted, in the same room but with a new wall flue. There are maybe £200-£300 of extra parts. So overall I expected quotes from local independents at between £2k and £2.5k. But have only had a quote for just over £5k inclusive. Are gas engineers now charging what they like?

Even when consuming 38500 kwh a year saving, say, 15% of gas will never make replacement worthwhile, even at April 22 prices. Grateful to hear if I'm missing anything!

QrizB

£2k to £2.5k is what I'd expect for a replacement boiler, fitted.

If you've only received one quote, and it's over £5k, it's because they've got a full order book and don't want your business right now.

https://www.boxt.co.uk are quoting me options from £2200-ish for a boiler replacement. What do they quote you?

theoretica

Seems time for a second quote - https://www.heatable.co.uk/  will give you a quote all online so you can see if it is in the same ballpark.  I did go with them in the end, the management was excellent, their local contractor I am less positive about.

fuzileer

Thanks - Good suggestion. I haven't tried BOXT yet because I wanted to go for local independents, but their online advertised figures do look more attractive. 

fuzileer

Thanks Theoretica. It does seem time to call time on the 3 local independents who I tried.

lohr500

We had a similar decision to make last year with our 35+ year old oil boiler.

I had managed to keep it running myself over the past 25 years or so myself, replacing several key components along the way. But according to the data I could find, it was only 70% efficient. I was also struggling to get parts for it and I was worried that the main jacket could start leaking at any time.

Also, our heating system relied on gravity circulation to heat the hot water cylinder and had no motorised valve control for the hot water or central heating circuits. This was also impacting on efficiency.

To give you an idea of cost :

To have the old internal oil boiler removed and replaced with a new externally located 36kW condensing boiler, the pipework modified to an S plan configuration, a large radiator upgraded in one of the rooms, pipework / electrics installed and fitted for a plinth heater (that I supplied), fitting of a magnetic in-line filter and removal of all the waste came to £5,110.
And that includes circa £2.5k cost for the oil boiler.

So I agree that the price you have been quoted seems very high in comparison.

Cardew

 I would agree with the £2k to £2.5k estimate above. Get BG to give you a quote; they are normally about 40% to 50% more than a good independent plumber which will give a ballpark figure.

With the post April figure of 7p/kWh for gas, your 38,500kWh will cost £2,700 so 15% savings(if achieved) will save £400 pa so it starts to make sense 

BUFF

Is your old boiler balanced flue, fan-flued or what?
What controls are you using currently?

I suspect that a modern condensing boiler (properly set up with appropriate flow/return temps) & load/weather compensating controls etc. may well comfortably exceed a 15% saving especially if your current boiler is not fan-flued.

How old are your radiators? You would need to at least flush them before installing a new boiler & modern radiators will use lower water volume & be more efficient.
 Also, if you are going to run lower flow/return temps for condensing you may need to increase radiator output/size (this also futureproofs you for eventual switch to a heatpump way down the line).

fuzileer

BUFF said:

Is your old boiler balanced flue, fan-flued or what?
What controls are you using currently?

I suspect that a modern condensing boiler (properly set up with appropriate flow/return temps) & load/weather compensating controls etc. may well comfortably exceed a 15% saving especially if your current boiler is not fan-flued.

How old are your radiators? You would need to at least flush them before installing a new boiler & modern radiators will use lower water volume & be more efficient.
 Also, if you are going to run lower flow/return temps for condensing you may need to increase radiator output/size (this also futureproofs you for eventual switch to a heatpump way down the line).

Thanks - A very knowledgeable response that I'll try to answer up to my limited level of competence. [1] My flue looks like an open flue up to a vertical chimney at the roof apex. [2] The control is a newish Honeywell STC9400 which we intend to retain. [3] Most of the radiators are quite old and we haven't had a flush for at least 10 years but would have them done this time.  [4] We hadn't planned to get into increase radiator size yet. Frankly we may have moved by the time heat-pumps become compulsory. Good to know that all this might well exceed 15%.  Thanks again..

BUFF

fuzileer said:

BUFF said:

Is your old boiler balanced flue, fan-flued or what?
What controls are you using currently?

I suspect that a modern condensing boiler (properly set up with appropriate flow/return temps) & load/weather compensating controls etc. may well comfortably exceed a 15% saving especially if your current boiler is not fan-flued.

How old are your radiators? You would need to at least flush them before installing a new boiler & modern radiators will use lower water volume & be more efficient.
 Also, if you are going to run lower flow/return temps for condensing you may need to increase radiator output/size (this also futureproofs you for eventual switch to a heatpump way down the line).

Thanks - A very knowledgeable response that I'll try to answer up to my limited level of competence. [1] My flue looks like an open flue up to a vertical chimney at the roof apex. [2] The control is a newish Honeywell STC9400 which we intend to retain. [3] Most of the radiators are quite old and we haven't had a flush for at least 10 years but would have them done this time.  [4] We hadn't planned to get into increase radiator size yet. Frankly we may have moved by the time heat-pumps become compulsory. Good to know that all this might well exceed 15%.  Thanks again..

Are you planning to simply replace existing with a similar but more modern, more efficient condensing conventional boiler (presumably your DHW is gravity fed rather than unvented?)? Or are you considering going to a combi or unvented for better shower etc. performance (assuming mains pressure is OK)?

If going combi you will have to change the Honeywell to something that complies with Boiler Plus. Tbh even if you stick with a conventional boiler then a control that can communicate with the boiler at bus level (e.g. Opentherm or similar) & do load/weather compensation will almost certainly pay for itself over the life of the boiler & potentially increase comfort levels.

You will have to have a system flush as part of the installation requirement for the boiler warranty. You will possibly also need a magnetic filter to comply with any extra extended warranty term that the manufacturer may offer (& of course inhibitor etc.).
I take it that you have TRVs on your rads?

I suspect that if you were to go down the full path of condensing boiler, properly set up, with load/weather controls etc. that it's not impossible that you might see nearer 25% than 15% (but I am not promising it ). That could save you potentially ~£700/year at the level of consumption you indicated & with gas at ~7.3p (the cap figure from April).
Assume a boiler life of 15 years & that's potentially over £10,000 saving over it's life (of course gas prices could fall back but equally they might climb further).

fuzileer

BUFF said:

fuzileer said:

BUFF said:

Is your old boiler balanced flue, fan-flued or what?
What controls are you using currently?

I suspect that a modern condensing boiler (properly set up with appropriate flow/return temps) & load/weather compensating controls etc. may well comfortably exceed a 15% saving especially if your current boiler is not fan-flued.

How old are your radiators? You would need to at least flush them before installing a new boiler & modern radiators will use lower water volume & be more efficient.
 Also, if you are going to run lower flow/return temps for condensing you may need to increase radiator output/size (this also futureproofs you for eventual switch to a heatpump way down the line).

Thanks - A very knowledgeable response that I'll try to answer up to my limited level of competence. [1] My flue looks like an open flue up to a vertical chimney at the roof apex. [2] The control is a newish Honeywell STC9400 which we intend to retain. [3] Most of the radiators are quite old and we haven't had a flush for at least 10 years but would have them done this time.  [4] We hadn't planned to get into increase radiator size yet. Frankly we may have moved by the time heat-pumps become compulsory. Good to know that all this might well exceed 15%.  Thanks again..

Are you planning to simply replace existing with a similar but more modern, more efficient condensing conventional boiler (presumably your DHW is gravity fed rather than unvented?)? Or are you considering going to a combi or unvented for better shower etc. performance (assuming mains pressure is OK)?

If going combi you will have to change the Honeywell to something that complies with Boiler Plus. Tbh even if you stick with a conventional boiler then a control that can communicate with the boiler at bus level (e.g. Opentherm or similar) & do load/weather compensation will almost certainly pay for itself over the life of the boiler & potentially increase comfort levels.

You will have to have a system flush as part of the installation requirement for the boiler warranty. You will possibly also need a magnetic filter to comply with an extra extended warranty term that the manufacturer may offer (& of course inhibitor etc.).
I take it that you have TRVs on your rads?

Yes - We're looking at a more modern conventional - probably the Bosch Greenstar 24Ri. Water comes from loft tank.
Control communicating at bus level is a bit beyond me I'm afraid but I can look into this.
Yes to the new System flush, new mag filter and existing TRVs.

Many thanks. Hoping this will take me beyond 15%!