I've been lurking her for a while, and have gained a great deal of useful information - thank you all!
There has been a lot of discussion on the merits of the various designs of HW/CH systems, on good v bad plumbers, the 'best' boiler. Our boiler needs to be replaced, and probably the entire system redesigned, as I am having two(!!) shower rooms added plus an extension.
Now, my diy is limited to analysis and putting up shelves (too old, fat and busy for much more). I've read all the posts about the merits or otherwise of combi v stored, open v closed, underfloor v rads, Worcester Bosch v Vaillant, but I'm having trouble putting all the information together coherently.
So, my question is: how can I go about finding someone competent to design a new system? From what I gather, 'my local plumber' probably ignored most of his theory classes in college, but who else is there? A college lecturer? Are there specialist consultants?
Don't put yourself down! If you can put shelves up you can hang a radiator! Connecting the pipes really isn't that hard. I found that most of the hard work is stuff like getting the tongue and groove floorboards up, drilling through walls to get pipes through, etc.
I've hardly ever found anyone competent enough to explain all the options to me...I'd never even heard of a thermal store before I started to read this group. (Seems like quite a few plumbers haven't heard of one either).
Often manufacturers are quite good sources of advice. I'm sure, for example if you call DPS and ask them about heatbanks they will chat to you for ages about the advantages of them! :-)
If you sketch out a design and post it on the web, some of the very generous experts here (I am not one) will probably offer some critique.
Don't worry: they will be quite friendly flames anyway :-)
How can somone design your system until you have decided what exactly you require.
Do you want UFH in place of radiators?
How much upheaval can you cope with, do you have space for seperate HW storage or is space a premium?
I would suggest putting your heating and plumbing ultimate desires down then look at which bits you really REALLY want and balance against what you will be happy with.
We got UFH from Nu-Heat, who will draw plans and design whole system etc as long as you can supply accurate floor plan including joist spacing/location etc.
Normally the people that supply the differrent parts will be able to suggest a capable installer of their own kit.
I found getting quotes from multiple plumbers was a good way of fishing for information and getting ideas that I hadn't considered at no cost!
I know what results I require, and I know what space is available; what I don't know is what is the best way to get to the results, and that's why I wanted to talk things over with a 'competent person'. I didn't want to go into vast involved detail on a first post here, but I'm happy to do so if your're prepared to read it! [see below]
First I'll answer the questions you've put:
Mr F: 'busy' = living in Norfolk and working in London. Yes, to be sure I could hang a couple of rads, but to do the whole thing would take me a couple of years, if not longer! I would be more likely to do the wiring; with the new regs I don't know if its worth it, but I am a lot more confident in that area (at least, the 3 houses I wired didn't go up in smoke).
Pete: UFH v rads - I'd love UFH, but this is a renovation/extension and as such it would be a very expensive proposition. Electric UHF is a no-no (my brother in NZ has just had this and is not entirely happy: expensive, slow response times). A wet system would be fine in the extension, but there really isn't enough floor area to be worth putting it in just the one area; to do the rest of the ground floor would require lowering floor levels, so not really feasible. Skirting rads are great (put them in my first house) but on the expensive side. Rads: well, siting them is always the worst problem, but that's what I already have in the main house. Hot air - mmmm, probably not feasible except in a new build.
Upheaval - there's going to be a lot of that anyway, so no worries.
Nu-Heat - yes, got their info, but see above. Their rule of thumb price came out at 4k for the parts, which is some way above what I would hope to spend.
As you say, the people who supply the different parts will suggest capable installers, but the problem is in deciding the kit in the first place!
I'm pretty sure most plumbers will gaily tell me that I want a combi boiler (and maybe moan that it has to be condensing), and either tell me that the current pipework and rads are fine, or that they are useless, depending on how much work they want to do.
So okay, here we go:
Its a 25 year old chalet, currently with living room, bedroom, kitchen and bath on GF, 2 beds + toilet on 1st, with loft space above. We will replace the upstairs toilet and some space in the 1st floor loft into 2 shower rooms. These will be directly over the kitchen, where the (gas) boiler is currently. Boiler definitely needs replacing; current system is open gravity feed, with a HW tank next to the upstairs toilet. Rads throughout; GF pipes are mainly routed in the concrete floor. All pipework is imperial.
Kitchen is on north side, facing boundary fence; neighbour's house is a garden away, so not too worried about 'clouds of steam' problems.
Bathroom currently has a bath with an electric shower over (Mira, quite acceptable performance) and is sited next to kitchen, so all HW pipework will be reasonably short. Obviously the current HW tank must move if it is to be retained and is to feed the new showers. Its not likely that 2 showers will run simultaneously, so I guess that doesn't rule out a combi? I had quite acceptable output from a Vaillant following a major renovation in my first house, so I'm not dead set against them. I do have a bit of an issue with running pipefuls of cold water just to wash my hands, and someone here was discussing recirculating the HW to eliminate this - would 'my local plumber' understand the idea? Equally, I would consider installing electric showers if the sums look better that way.
Usage: 3 adults, with varying schedules (one night worker, one [me] away Mon-Fri).
I have no idea what the gas or water pressures are - should I try to find out? Its a hard water area, BTW.
Is there an advantage in changing to a closed system? Will retaining old rads/pipes potentially cause problems? Should I get a pressure test? If its agreed that replacing some/all of the CH, should I look at minibore? microbore? or is bigger better?
And what type of boiler? From what I'm hearing, Worcester/Vaillant/Keston is the way to go for a combi, but is that really the best option here? And is it better to go for an all-in-one option and lose both the HW and CW tanks, or is that putting all my eggs in one basket when it gets ill?
I daresay I haven't given all the info needed, but for those who have read this far, your input will be appreciated! It all seemed a lot simpler in
1983 on my last big project... but that was a 'back to the brickwork' Victorian terrace renovation.
It has to be condensing now My rads and pipework are being replaced as the pipework was a single pipe system not seperate feed and return
check that the pipes are isolated from the concrete (lagged) or corrosion can result
Keep an electric shower as its handy for when the boiler packs up
I've just had an Alpha CD50 fitted, this gives instant hot water ( only dependant on pipe length )
Check out the Alpha CD50
And
Keep an electric shower
Note :- I have no expertise in this field, i've just done a lot of research due to having a large extension, the new boiler will be feeding 2 bathrooms and an ensuite with 2 adults, 2 teenagers, and and OAP and we shower with the occasional bath. So this combi is ideal, instant mains pressure hot water and never runs out
You should be giving out the advice, your analysis is only a tad more cynical than the reality.
The only consideration on the gas will be the distance from the meter to the boiler - you may need an upgrade to the pipe work especially if you choose a combi.
The water pressure is an issue if it work the electric shower the pressure must be OK. If the sink cold tap is given >16 ltrs/min then the flow is OK.
see The SealedCH FAQ.
Will retaining old
It's worth trying to reuse them as replacing them will be very disruptive. If the installer is aware they are imperial there should be no problem.
Should I get a pressure test? Yes.
If its
If you replace the pipes entirely you may find that a microbore system make for less disruption.
They are reasonable makes combi, system or plain heating.
And
If you go combi you might as well lose the CW loft tank.
I renovate house for a living. From what you have said I would do this. I always go for one-box solutions in heating and DHW, the combi, to save space, after being bitten by useless thick plumbers, who wanted to put tanks and cylinders all over the place. They are also highly cost effective. Thanks to IMM, and others, here, I know that combis can supply two and more bathrooms. The high flow rate models are usually floor mounted, and tanks and cylinders are done away with. A combi will heat the radiators of a very big house.
You say two extra showers and retaining the bathroom, which is 3 showers. Firstly see how much the water mains can deliver in flow. Time a bucket from the kitchen tap or outside tap to get litres per minute. If it is below 30 it is worth getting the water mains renewed to give to greater flow. Once done it is done forever and well worth doing.
Then it is a matter of getting the right combi box. The ultimate and RR quality, at about =A32.3K is the ACV Heatmaster (see current thread on this). Look at the Viessmann 333 (also RR quality), Potterton Powermax and Gledhill Gulfstream. Any of these can go in the loft space (over a load bearing wall) and supply the three showers with high pressure mains water. With combis it is the "flow rate" that matters.
In the kitchen look at fitting a Myson Kickpace fan heater, taken off the CH pipes, under the units. They save a lot of space and warm your toes by blowing hot air across the floor.
Decide what you "need" and specify that to your heating engineer or plumber. Know what you want before and don't be persuaded otherwise.
Strange. All I ever hear of is 'thick plumbers' wanting to rip out perfectly serviceable 'tanks and cylinders' and replace them with a 'one box solution'. Because it's the easy way for them to maximise profits, and they don't give a stuff about performance.
No, pet. It's *exactly* what failed plumbers like you say. Who can't plumb or design to save their life so want an easy 'one box' solution. But don't have to care about the later problems of being tied into that maker for spares and servicing, leaving that to the poor fool who took their advice.
Doh. You forgot to mention eco-hometech (MAN boilers) COmes with built in weather compensation and varios models have significant flow rates right up to 21 l/min !
are always installed in situations they cant cope with.Go for a unvented hot water cylinder of about 170ltr capacity.Couple this up to a 30kw system boiler or there abouts depending on output required and stick with the rads.Cant believe you cant find plumbers who cant specify systems like this.
This might be an excellant system for a newly built house. [With perhaps a rather smaller HW cylinder - 170 ltr is the size I have used for a 6 bedroom - 3 bathroom house with a 37kW boiler]. This is, IMHO, somewhat OTT for an existing 3 bedroom house. The cost and disruption of digging up the water main to provide a minimum 25mm mains supply could easily be comparable to the rest of the job.
You are welcome to your view but I think it is arguably OTT.
Misadvise. Yes, and get a an expensive BBA approved plumber to fit it, and every year have him expensively service it too. A "BBA" approved man has to service it, not a corgi man. Heat banks are superior and don't require a yearly service. Over 20 years the service cost of an unvented cylinder will be far more that the original cost. Skip a service and have a serious water leak and the insurance company will not pay up. An unvented cyldiner is a waste of time as better alternatives are around.
Best they stick with the high flowrate one-box solution. The Viessman 333 and others have already been mentioned on this thread. The wall mounted Alpha cd50 is quite good too.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.