New boiler location and ultimate setup recommendation please

[Pizzaboy]

Thanks anyone for reading

Looking for peoples views of best setup, location and any points to consider that I don’t mention please

2000 built home, 4 bed, family bathroom, en-suite, downstairs toilet, radiators

Currently set up with gravity fed system. Showers are a terrible. Want to rip out everything and start over, without Compromising at any point. Aim is never to feel a change in temp or velocity of water, up to 2 showers run simultaneously

Leaning towards unvented cylinder, new boiler, 22mm new cold supply, accumilator.

Guesstimate my flow rate to currently be 12ltrs per minute using kitchen sink test. So that’s why I would install new supply. Not sure about pressure. Probably ok. But not amazing. So I’ve read a accumulator helps that.

Been offered by first plumber 42kw combi. But I’ve read that doesn’t matter what the boiler is capable of. Unless you can get succifiant water coming in. You can’t run 2 decent power showers simultaneous. So ruling out combis unless I missed anything on this

Would ideally like to move boiler and unvented to loft. A full unvented setup is massive and a complete eyesore. Would be prepared to fully board and insulate roof. But I keep reading frost will affect boiler even with frost free. Not sure how cold Loft will get once insulated. But without a radiator up there. I would speculate it won’t be much above freezing most of winter. So this puts me off. Any comments positive or negative on this. Or fixes

If I go with loft I read this:
Gas, water, and electrical isolation points should be provided outside of the roof space so boiler can be isolated without gaining access to roof space. Lag pipes. Especially the “condescending pipe” ?
Anything else anyone can add please

Also running a new 22mm water supply up the side of the house to loft. Will this mean I’m going to loose a ton of pressure? Really wanting to avoid pumps. They noisy and one broke down on me in year. So have little confidence in something with that many moving parts. So if I do loose pressure something to help with this. I believe accumulator is the answer

Other questions
Is g3 certified the same as gas safe or are they different qualifications

Probably will change radiotors. Will there be change in pressure in the central heating with the new setup. How likely is any of my pipe work connections gonna give way with new pressure and need accessing and sealing

Any other factors and considerations? Please

There is a option to put it all in an internal garage. But this means I would use a ton of useable space and take away the option to convert the garage in the future. Without garage heating, I can’t see it being much warmer than the loft.

current cylinder is in a airing cupboard on floor one. But I don’t think you’d get a Unvented in there

cheers

 

[centralheatking]

You already well informed compared to some whom ask this question. I think your first action is to accurately test your incoming water for
1. volume. 2. Pressure.......they are separate but inter related. Test at a reliable place like an outside tap. Not at a tap with reducers or fancy airation inserts Test at specific times. Sunday morning 7am when demand is least
Weekday morning 7.30am and NOT in school holidays when the demand peaks.
Then we will know what you are dealing with. Where are you because some areas are diabolical. the suppy crawls out of the main. centralheatking

 

[gmartine]

The system you want is right but where to locate it?

Convert the loft and stick it in the garage, it's an almighty faff to do a loft install plus folks despite the actual risk of failure tend not to like the thought of many hundreds of litres of hot water residing above their heads. Temperature shouldn't be an issue for either if everything is insulated (even the boiler) and you need G3 qualified engineer to install an unvented cylinder.

 

[centralheatking]

The system you want is right but where to locate it?

Convert the loft and stick it in the garage, it's an almighty faff to do a loft install plus folks despite the actual risk of failure tend not to like the thought of many hundreds of litres of hot water residing above their heads. Temperature shouldn't be an issue for either if everything is insulated (even the boiler) and you need G3 qualified engineer to install an unvented cylinder.

In the garage all day long wack a honeywell frost stat in the coldest corner near the door
off you go....get two quotes loft or garage its obvious which one will be cheaper and thats the best location ...centralheatking

 

[Brambles]

Loft or garage, combi or unvented?? Everyone you ask will have a slightly different perspective. Only you can choose.

The only point I would be (very) uncomfortable with is running the 22mm mains supply to the loft externally to the property.

If you opt to go down the (pumped ?) accumulator route - I would not consider installing that in the attic.

If you go for the loft installation, the area must be properly prepared with good access and support for the UV tank. Without teaching you to suck eggs - the limiting factor is (in my experience) hatch size and overhead clearance to get a decent UV tank into place.

 

[centralheatking]

I saw that regarding mains supply water externally thats is a no no and would cost extra gas to bring it up to hot water temp, then it freezes ...bin that idea right away chking

 

[muppetman74]

OK, I'm not a plumber but was in your exact situation last year. 3x bathrooms, downstairs toilet in a large victorian semi, gravity-fed. Also 15mm mains feed, 13 litres per min at garden tap with 3bar.

Like you I considered a large combi, but having spoken to people who had actually had this done, it wouldn't sustain 2 high flow showers simultaneously, which was my requirement.

I did a lot of research and decided for an unvented cylinder and an accumulator until I could upgrade the mains feed (it's under the front driveway which I'm planning to redo in a couple of years). In the end, had the unvented cylinder fitted while waiting for the accumulator to come into stock (it was on 3 weeks order). The flow and pressure was so good out of the unvented cylinder I ended up cancelling the accumulator order and haven't yet upgraded the mains supply to 22 or 28mm. I don't really need to upgrade it but will end up doing so when the drive is being done as it would be a shame not to.

Guess what I'm saying is have an unvented cylinder fitted and see if you are happy. If not, upgrade your mains feed. If still not happy, add an accumulator. You might end up saving some cash.

 

[EvilDrPorkChop]

Another vote for the garage too. If your cylinder leaks in future then I wouldn't want it leaking through my ceiling, at least in the garage it can do little damage. Also from a maintenance point of view of servicing etc it's a lot easier. And you notice things when they go wrong, when it's tucked away in the loft you'd only know there's a problem when something starts leaking or something stops working!

I'd bet it's easier getting a new water main to the garage too than the loft....

 

[gmartine]

If temperature is a real concern for either boiler location especially if the system is going to be off at critical times and for long periods you can always use an antifreeze protector like Alphi 11, pricey to dose a large system at the right levels but that is relative.