New Boiler - Combi/Megaflow Costs

[sniffy]

Hello Troops. We need to make a decision about a the boiler and I'm after some advice.

Currently we've got a big 3 br terrace with an old cylinder system but a newish (3-4 YO) British Gas Condensing boiler. The shower pump has gone and a stratospheric gas bill for the winter has lead the missus to talking about a new boiler.

We got 2 quotes for replacing it all with a Wor-Bosch Condensing Combi for around £3500. These seemed very expensive and I've read that a megaflow/pressurised system is better for houses with multiple users. [We've only 1 bathroom but there's 2 of us + 2 toddlers.] I know water pressure is an issue with megaflow systems but one of the plumbers said we had very good pressure.

So some questions:
Is £3500 taking the mickey for a Combi - (in London)?
Is Megaflow a better option?
What ballpark would we be looking at for the Megaflow?

Thanks for any insights.

 

[doitall]

First it's no good guessing the mains pressure or flow, you can time how long it takes to fill a 5Ltr bucket, at peak and off peak times, and any good plumber/engineer will have a gauge to measure the pressure.

Expect £2.2k ish for a megaflow using the existing boiler.

The average price for a combi swap outside London would be less than £2k, so depends where you are and what the parking etc is like.

New boiler and Megaflow £3.5k.

 

[D_Hailsham]

Currently we've got a big 3 br terrace with an old cylinder system but a newish (3-4 YO) British Gas Condensing boiler.

Unless there is something wrong with the boiler, you won't see any savings just by changing it for a current model. The boiler has to be paid for and it will take ten years or more to recover the cost.

Which model boiler do you have at present?
Does your hot water cylinder have an integral insulation jacket?
What controls do you have for heating and hot water?
Is your house insulated? There are deals available to get cavity and loft insulation done cheaply. Check out Energy Savings Grants

 

[sniffy]

Thanks for the responses. To clarify things:
-The current boiler is a British Gas 330.
- I think the cylinder is insulated - will need to check. I gather from a few plumbers that it's quite small for the system.
- There's a timer system for the boiler and a thermostat for the heating.
- We had the loft insulated with 270mm insulation with a grant last winter. No cavities to insulate

Would we be able to keep the boiler to use with a megaflow?

I guess we were looking into replacing it because of the cost of replacing the shower pump and the annoyance of running out of hot water reasonably frequently.

 

[doitall]

Yes, you can use the existing boiler with an un-vented cylinder.

You do need to get the figures for the mains supply though.

 

[Deleted member 105431]

the boiler you already have is a rebadged glow worm hxi and is very efficent if adjusted correctly and you have some good controls. It might be worth getting a glow worm engineer to service it and set it up properly as bg are useless. The best way of saving money is it insulate your house such as the loft and cavity walls. Insulating pipework in the airing cupb will help and turning the boiler temperature down.

 

[sniffy]

Interesting...
Sounds worthwhile - I don't know when the boiler was last serviced (we moved in 12 months ago). I'll check the insulation in the airing cupboard too.

Any ideas what it would cost to fit a decent shower pump? Our existing one was fitted under the bath and sounded like a 747 until it finally died.

Doitall: £2.2kish for a megaflow (with existing boiler) vs £3.5k for a combi seems a no brainer - pressure allowing. Why didn't my plumbers talk to me about it?

 

[doitall]

As Dangermouse posted, you have a good boiler, you would be better upgrading the hot water side.

The guy can maximise profit but chucking a combi in whether it's a good plan or not.

You should check the mains out and get a couple of quotes for an unvented cylinder.

Remember they must hold a G3 unvented ticket, and don't let anyone near it that hasn't.

 

[bengasman]

Chances are that the rads are not balanced, the bypass is too far open, the trv's on max, and the boiler and cylinder stats are set too high.
The result is the boiler will actually do little condensing and be on far more than necessary.

Before you do anything else, get somebody to balance the system, and set the thermostats and timers more economically.
Change the timer to one that has fully independent timing for ch and dhw, so they don't have to be on at the same time; this will improve the performance significantly.

As mentioned before, a different boiler will give little or no improvement.
I had a similar job last year where they had a gasbill of over £100 a month for a 3 bed terraced, and that was before the massive price increases.

 

[sniffy]

Thanks for the brilliant responses. Our gas bill last winter was £100pm (on a very cheap tarriff)! Sounds like we really need a service, setup and some quotes for the megaflow.

But how do I find someone decent? Should I get Glow Worm to do the service/setup? It sounds like the 'decent' people I've always used are taking the p*ss. I've had some woeful experiences going through the Yellow pages etc. A google of 'G3 unvented' doesn't come up with much other than courses. Can anyone recommend anyone who can do the service/quote on an install? In London NW10?

 

[doitall]

Click on "agile" name and send him an email, don't know if he covers nw10 but it must be close.

 

[D_Hailsham]

But how do I find someone decent? Can anyone recommend anyone who can do the service/quote on an install? In London NW10?

Use Trustmark

 

[bengasman]

But how do I find someone decent? Can anyone recommend anyone who can do the service/quote on an install? In London NW10?

Use Trustmark

Same sort of thing as the current corgi scam: start off paying a fee, fill out a form and pay another fee, and then finally pay some more.
A perfunctory assessment, and you are in. It has to do with paying and boxticking, not much else.

 

[bengasman]

If Tony "agile" is willing to do the job, hire him, you will be well looked after.

 

[D_Hailsham]

Use Trustmark

Same sort of thing as the current corgi scam: start off paying a fee, fill out a form and pay another fee, and then finally pay some more.
A perfunctory assessment, and you are in. It has to do with paying and boxticking, not much else.

I don't think you have even bothered to find out what Trustmark is all about. You are just making preconceived generalizations.