Plumbing, heating and water system for 5 bed, 3.5 bath house - recommendations pls

[thesaurusgirl]

Posting for my parents.

House has had no work done since 1979 so it's a total gut job. Plumbers coming round to quote later this week but here's the wishlist and Mum would love some recommendations of models, brands etc.

2 bathrooms currently, but future proof for 3 bathrooms and a downstairs loo
Really powerful water pressure (even when three showers are all going at once)
Instant hot water
Hot water that never runs out
Minimal variation in temperature (so doesn't go cold when someone flushes a loo or runs at tap)
Gas fire in sitting room
Gas 5 burner hob
Victorian radiators throughout
Trench heating in kitchen along bi-folds
Wet underfloor heating in 3 bathrooms and hallway
Controllable heat
Mains water softener

What have we forgotten? This is my parents' last home, they want it to be minimal maintenance, and to be able to entertain Air BnB type paying guests as well as grandchildren. They are not millionaires but they're downsizing so budget is less of an issue than performance.

Thank you all for advice (makes eyes at PigletJohn).

You will need extra-large pipes and valves on the softener

A Megaflo or similar. It will be bigger and heavier than the cylinders you are used to.

You will almost certainly need to run a new, 32mm blue plastic water pipe from the pavement to the softener and 22mm copper all the way to the cylinder, and 22mm pipes to the bath taps.

For a start, fill a bucket at the kitchen cold tap, and the utility room and garden tap if you have them; time it; calculate how many litres per minute it delivers.

A combi is no good.

Are you in or near a major town?

Will you have solar panels?

Thank you PigletJohn, knew you'd come to the rescue!

Mum is having a 32mm pipe installed, my sister had this done at her house of a similar size, it was £3k but has transformed the water pressure.

The new house is in a major town (in fact MNetters' advice helped Mum find it!)

No solar panels AFAIK although both parents definitely intrigued about the possibilities there.

Megaflo has been mentioned but don't they all run on timers? Mum wants to host visiting students to supplement her pension and it's possible they'll all be in and out at odd times of day.

No, a Megaflo and other brands are just a fancy kind of hot water cylinder, which is pressurised and capable of a large and powerful flow. It is usually heated by a gas boiler, and will call for heat, firing up the boiler, when its thermostat detects that it is not fully hot. They are often 250 litres or so, and in an ordinary domestic house you only need to run the boiler a few hours a day, as it is slightly more economical in gas than frequent small top-ups. If people may be having baths and showers at odd times you can let it heat up each time water is used. Once it has been heated, you might get three baths or six showers before it is cold. If the boiler is turned on awaiting demand, it will start replenishing the cylinder while you are running the bath, so will never get cold.

It is usual to have an electric immersion heater (or two) fitted so that you can have hot water if the boiler is out of action. If you have solar electric panels fitted, you can use any surplus free electricity to heat the cylinder. An immersion heater warms about one litre of water per minute (boilers can be ten times as powerful).

We're going for a thermal heat store (550l). It can connect to solar hotwater heater, a woodburning stove, and a boiler (it is programmed to find the cheapest heatsource first). It should be sufficient to do what we need (which will ultimately be the same set-up as you) though for us it makes more sense as we live rurally.

Hugely helpful, thank you both.

Malice, what brand, model etc. are you getting? Though sadly no woodburning stove for my parents, gorgeous idea but just not practical in a minimal maintenance home. (Dad's already excited about his remote-control gas fire).

PigletJohn If you were specifying for your own house and money was no object (final salary pension) which boiler and Megaflow tank would you want?

There seems to be a lot of variation in price so we want to have an idea of what exactly we ought to be asking for, and how much we may expect to pay.

Thanks again for allowing me to pick your brains like this .

I would get a Viessmann system boiler and a Megaflo or Santon. Neither would be in the loft. If I was building a new house I might have wet UFL in the hall.

Reason for asking if you are in a town is that you need a good installer who is approved by the manufacturer and has been on their training course. In my small town there was only one Viessmann firm and he has now retired, so I have to get one from another town.

On their website they have an installer search facility.

UFH in the hall

Because heat from a radiator rushes upstairs so halls are often cold even when landings are hot. Concrete floor with UFH is a wide, large, low temperature heat source so stratifies less. The hall might be tiled.

Well now you've put the cat among the pigeons PigletJohn, we'd been told not to touch any brand except Worcester Bosch or Vaillant.

Plus the Megaflo cylinder will need to go in the attic, because there's nowhere else for it. Could it possibly go in the cellar? Although the house sounds large on paper it's just a terrace townhouse, so lots of small rooms in a tall but not wide footprint.

What's the cylinder capacity we should be asking for? Bearing in mind 4 students or 5 growing grandchildren can spend an awfully long time in the shower or bath. Is there anything we should consider about the power of the boiler?

The wet central heating is divisive too. The house is being gutted so it's a possibility but won't it change the floor height everywhere? Surely you'd constantly be stubbing your toe?

Sorry for so many questions, you should hire yourself out as a consultant to MNers, I'd pay . [Thanks].

We have have a Viessmann boiler (actually 2, but only use one) in a 5/6 bed house with 4 bathrooms.

What's wet UFH as opposed to dry UFH?

We have a modernish house, but v hard water area, and turning 1 bath into 3 baths so current boiler won't cope. Shall I get a megaflo?

thesaurusgirl, please do feedback what you're going for when your parents have decided!

Have a look at the Which survey and see what three brands come top.

One of the three is a large German company which is not so common in the UK, hence my question about towns.

The cylinder can go in the cellar if you want. It is undesirable to have it in a loft where you need a ladder, it may be dark with poor flooring, and may be freezing in winter. The cylinder is very well insulated but there will be pipes as well.

Some maintainers now refuse to work in lofts unless there are guard-rails round the hatch, fixed access, proper floor and lighting.

Wet UFH is OK if you are building the house or laying new floors, hence no step. I would not bother retrofitting it. Concrete forms a heat buffer so maintains a more even temperature in a hall. You did ask what I would have.

250 litres is common for an unvented boiler. You can get a 300 if you want. A shower or bath might be 2:1 hot and cold fill. A bath holds about 100 litres. A powerful shower might use 20 litres per minute. The boiler might replenish the cylinder at about 10 litres per minute, so by the time the three people have had their bath, towelled off and cut their toenails, it will be ready for the next lot. Most of the time the system boiler will try to run at half or a third of its maximum power, which is quieter and more economical. You may have noticed that combi boilers, when running a bath or shower, are noisy. This is because they are running flat out.

A system boiler will not usually need to run flat out unless you have used all the hot water and the cylinder is fully cold. It will then modulate down as the cylinder warms up.

The installers will calculate the boiler power required to heat the house. Explain about your bath needs and they will size for multiple baths at the same time as all radiators are on for a cold winter evening. I expect it will come out at about a 30kW boiler.

Wet UFH has hot water pipes in or under the floor.

Dry UFH has electric cables embedded in the floor.

Energy from electricity costs about three times as much as energy from gas.

Thank you thank you PigletJohn, that's so helpful. Your knowledge is on these matters is incredible.

We're going with a company called HTG Engineering, based in Market Rasen. The idea is a simple one and the system is modular - insofar as it uses widely available parts and fittings. It's defnintely worth a look.

to all.

REALLY helpful advice, not least because I've now been able to compare prices on the internet.

300 litre Megaflo costs about £1100 inc. VAT

Worcester Bosch Greenstar 40KW boiler about £1500 inc. VAT

Rather a lot cheaper than some of the estimates we have been given, and all exceeding the capacity recommended by PigletJohn so will hopefully come out in the wash cheaper still.

Stubbed toes are not a problem in the hallway so we will definitely go for a retrofit option on that, a company called Nu Heat has a system called OneZone which should do the job, unless anyone has other recommendations.

Will definitely update on what Mum goes with, have learned so much from MN when doing my flat so it would be great if this thread helps others.

Thanks thesaurusgirl, I certainly would be v grateful for your feedback! We are doing the entire heating and plumbing overhaul for 4 bed, 3 bath 220 sqm house and any recommendations are very helpful.

If you have several bathrooms and a Megaflo, you will need a very good incoming water supply. Unless the house is quite new, you can expect to need to run a new plastic waterpipe out to the main under the pavement. This is fairly easy if you have gravel, flowerbeds and liftable wooden floors, but more tiresome if there is a lot of concrete in the way.

You will be amazed what a difference it makes

Our house was built in the 60s, I'll keep this in mind, god knows what size the current pipe is!

15mm copper I expect. You can see it at the stopcock. Fill a bucket at the kitchen cold tap, and the utility room and garden tap if you have one. Time it and calculate how many litres per minute it delivers.

Will do PigletJohn!

We have discovered that our hot water storage tank is ONLY powered via electrical immersion

I'm wondering if we may as well just get solar panels as the central heating engineer did say it would be costly to get a new storage tank (on 1st floor) and then fit it to get hot water from the gas boiler (in the basement).

On a positive note the existing gas boiler is more than adequate to run the central heating...

Dh works from home, there are 6 of us so I think we will make plenty use of the electricity we generate ie. can run appliances including tumble dryer during daylight hours!

Energy from electricity costs about three times as much as energy from gas, so that is a poor deal.

Although you will probably get enough electricity from solar panels in summer on most sunny days, my solar contact tells that in winter you might only get 20% of the panels' rated figure.

Give serious consideration to changing the cylinder and having it fed from the gas boiler. There will be a way of calculating the annual money saving, but I don't know how to work it out.

How much electricity do you use in summer, per month or quarter? Use actual meter readings, not estimates or direct debit amounts.

What colour is your cylinder? What markings are on it? Post pics if you can.

p.s.

the hot water cylinder can be anywhere. For example it could be in the basement next to the boiler, reducing pipe lengths and difficulty. You still need a pipe between the cylinder and the taps, but there must already be pipes covering quite a lot of the route.

It's small about 120 litres the guy said with a green coating.

The boiler is in the basement space that is about to become the kitchen so can't have the tank in there. Also boiler in back of house current tank in front of house... Also wouldn't I still need the header tanks

Originally I was excited about having a mains shower in the basement from the stored hot water . We already have one decent new electric shower.

Realistically the hot water would only be needed for washing up (have dishwasher), washing hands and perhaps daily bath at most (I would anticipate less as they all shower)

ARghhhhhhhhhhhhhhhhhhhhhh I just want someone to tell me what to do for the best.

Would a thermal exchange cylindar and then using the gas boiler be the long term best?

120 litres and green is fairly typical. and reasonably modern. Maybe ten- years old perhaps. Not heating it from the boiler was a poor and unusual decision by the previous owners.

Have you decided to get a new water supply pipe? If so, no contest, get an unvented cylinder, and heat it by gas boiler, or immersion when the sun is shining on your solar panels or the boiler is out of action.

The markings on the cylinder may be important. It might say "direct" or "indirect"