Price of new boiler/megaflow/central heating system

[Artyjools]

We are carrying out major refurbishment/extension works to the house we moved into a year ago and so far soooo much stress. One of the things we are finding hard to deal with is that our very detailed spec/price doesn't appear to be worth the paper it is written on.

When we bought the house, we knew it needed a new boiler, but when we moved in, we realised it needed a whole new central heating system. Apparently, this one is a single pipe system - you can't switch one radiator off - and there are no TVRs.

Anyway, we asked the builder to quote for new radiators and we talked about hiding the pipework in the walls, as they are currently running vertically down the walls (yes, really!).

The quote is about £11k for a 300 litre megaflow, a worcester bosch condensing combination boiler and 14 radiators. There is extra for fitting hot and cold feeds and fitting sanitary ware etc. We are living in the house, but most of the floors can be lifted as we are having new flooring.

The builder has now said that he didn't realise that new pipework would be needed and that would cost an extra £3k. He says new pipework is needed because the new system will be presurised and the old pipes may not take the strain. We have already had some debate about whether the flow will be enough and whether we might have to add some sort of gizmo to improve the flow at a later stage.

Quite apart from the fact that we assumed that a new system would mean exactly that, it all seems very high to us. Are we out of touch with the price? We are in the south-east.

Also, do we really need a presurised system and a megaflow? We really do not have a clue.

[mylovelymonster]

I don't know - sorry - but how is your relationship with your builder?

Could you consult some other heating engineers/builders without his knowledge at first, to get alternative quotes? Or press him for a detailed breakdown? Can you get someone else to do that bit? How are you staging your payments and what leverage do you feel you have? any use?
I would think any deviations from your priced spec should be priced out very clearly.
Sorry you're having hassle.

[Artyjools]

Hiya - I guess you could say our relationship with the main guy is a little wobbly because we keep getting deviations from the price we had agreed. He is saying that he employed a quantity surveyor to do the quote but that he was rubbish and hadn't included what he should have included. Our view is that we don't have the expertise to know whether the spec/quote is complete or not and that was up to him to check what the QS had done. His quote wasn't really cheaper than the others - we just felt we could trust him to get the job done. It's not all his fault. Our structural engineer messed up big time, which cost us 4 weeks and put the builder in a difficult position.

I am getting another plumber to come round and give us a quote for the job. One of the main issues is that we just don't understand what this megaflow/combi boiler/presurised system is all about, and whether there is something cheaper that would suit us just as well.

[Tansie]

I am absolutely no expert, but surely it's a combi boiler or a Megaflow choice, not both?

We had a Megaflow installed in our 12 year old house a year ago, mainly because our shower pressures were rubbish and the existing system was as old as the house. We were told that for a 4 bedroom and poss 5 person family, we'd be better off not going for a combi-boiler, something to do with capacity; it was suggested it'd be good to have some water storage capacity should we ever go for solar hot water (unlikely!), and we have mains water you could cut concrete with.

We were warned that our radiators might spring the odd leak once the CH was pressurised (and I think we were told that was optional- NO idea how that works!). They did (2 of them) but the plumber fixed that for us on the spot.

Anyway, we bought a Megaflow 270 which is a size up from what we really needed. Installing it in the loft, and removing the hot water cylinder from the airing cupboard cost £3000. And, oddly, our hot water is more pressurised than the cold!

[HidingFromDD]

You do need a boiler with a megaflow system. We had this with our old house and it was by far the best combination available (5 bed, 2 bath) as it allows 2 people to shower at the same time with no loss of pressure.

It is high pressure though so can expose weaknesses in pipework. Also, 14k for the lot sounds very steep to me. I think we paid around 8k for similar (although can't remember if we replaced radiators, probably not)

[mrswee]

I think that sounds very expensive.

we are replacing heating in our 3 bed flat. we are buying in the boiler and radiators ourselves.

the wochester bosch combi is £827, 7 radiators various sizes are round a total of £600. Flu and timer and valves £400-500

The fitter is getting the pipe work and fitting, the total should come to £2500. It's cheap as he is a friend and has worked out the best way for us to do it.

I appreciate yours is a bigger house and a bigger job but £14k is a huge lot more that £2500.

I'd see what someone else says! he may not be giving you the best advise on what you need for your house either.

[RationalBrain]

We've just had a new megaflow and boiler, plus reconnecting 2 other rads, cost of about £6k. (3 new rads as well, but these were prices as part of the main extension cost)

I think an extra £5k plus £3k for the rest of the system seems pretty steep, although recessing all the pipes will be a bit of a job (we've boxed lots of ours in, but still looks crap). The only way to tell is to get another quote in.

Re whether you need a megaflow - well, that depends. There are 3 main options for HW/CH (this is my laymans interpretation from having just gone through this!):
-old style h/w cylinder and cold water tank in loft (gravity fed). The pressure can be a bit rubbish for showers though, so you might need a shower pump.
-megaflow (pressurised) cylinder - means all h/w and cold water comes in straight at mains pressure. No cold water tank needed in loft. Assuming your mains pressure is sufficient, you'll have great showers. You can't add on a pump if its not sufficient though, so you need to check beforehand. More than one person can have a shower at once, as the pressure won't drop.
-combi boiler - no cylinder or cold water tank, all h/w and cold water comes through this, so you can only have as much h/w as it can heat as it goes through (you can get higher and lower powered ones). If more than one tap is run, then pressure is halved between them, etc, so a bit rubbish for larger households.

HTH!

[Artyjools]

Thank you everyone - this is so helpful as I have struggled to understand it up until now. We do have two showers at the moment and they are both really powerful, but we shall have a third. They are unlikely to be used all at the same time though! It sounds as if we could keep to the old style system and have a shower pump for the new shower or go for the new system and test the system using the old pipes and then, if there is a problem, replace what needs to be replaced.

The builder says he isn't making anything on the plumbing side, so we shall get a couple more quotes as it does appear to be steep.

Thanks again

[Tansie]

Glad you're feeling better informed about the arcane mystery that is plumbing!

One small point- you don't mention that your powerful showers are electric 'Power showers'. If they aren't, no prob. If they are, apparently you can overload your house main seriously having more than one PS running simultaneously, or if someone switches on a powerful hairdryer, even!- that's why we ended up getting a pressurised system not 2 electric power showers to overcome our poor shower pressure problem.

Also, if you're in a hard water area, it might pay to get a softener installed at the same time, making sure to check that that extra impedance doesn't lower your water pressure too much.