Boiler and tank questions

Matt_Hirst · 3 Feb 2017 at 12:51

We live in a 4 bed detatched house, approx 17 years old, it has a convential family bathroom and also an ensuite which has full bath separate shower etc and downstairs we have a separate toilet.

We've just had the family bathroom done but find the shower is pretty poor pressure wise, the plumber who fitted the new bathroom now recommends fitting a pump to boost the pressure of the system. We are intending having a new bathroom fitted to the ensuite and the downstairs toilet done.

We currently have the original ideal classic boiler with water tanks in the loft and a tank in an upstairs cupboard.

Speaking to a different plumber he said no don't do that fit a combi boiler it'll cure all issues.

Finally speaking to a third plumber he said if it was his house he'd fit a pressurised tank system.

So three different plumbers three different recommendations - but I haven't a clue as to which will be best option.

Theres four of us living in the house, two kids one 11 one 5 and I assume as they get older water usage will increase.

So any thoughts?

Matt

Burned_Alive · 3 Feb 2017 at 12:55

Generally for a house that size and potential usage a combi isnt recommended as it cant happily feed two showers at the same time.

A pressurised tank system is probably the best option but could be the most expensive, so just fitting a pump to the existing system may be your best option.

Matt_Hirst · 3 Feb 2017 at 13:16

Wed been put off the pump due to the noise they reputedly make and was told they were unreliable as well.

The pressurised tank was mentioned it was more expensive option but we have no idea as to what is meant by it is the most expensive option, are bills going to double, triple?

Matt

DXP55 · 3 Feb 2017 at 13:55

Most expensive option to fit - Works same as tank system but totally sealed and you get mains pressure at hot taps.

Wish I had done it as combi sucks and there is only two of us.

a1ex2001 · 3 Feb 2017 at 15:34

Do you have both showers off the tank or is one electric?

If you only have on off the tank then fitting a pump or combi will likely improve the situation the combi will only make it better if you have good mains pressure and flow.

If both showers run off the tank fitting two pumps is likely to drain it pretty quick depending on the size of cylinder if you run both showers and a combi won't help at all! The pressurised system with an appropriate cylinder is the ideal solution but will cost more.

We have two showers one electric, that is pump fed from a cold water tank in the loft and one combi fed this means we can run both at the same time and still have a shower if the boiler is out. I would have gone cylinder but our terraced house simply doesn't have the space!

Matt_Hirst · 3 Feb 2017 at 16:16

Both showers are fed from the tank, though there is nothing to stop me fitting an electric one in the ensuite.

However the shower we had fitted in the main bathroom is what highlighted the poor flow problem.

Matt

Jez · 3 Feb 2017 at 16:19

I just got a pressurised system commissioned literally today. Utterly amazing and really wish i had done it sooner. To have mains pressure hot water is something i would always immediately fit to any house i were to live in now. The showers all run at the same time happily, and are as powerful as i have ever experienced in any upmarket hotel or anywhere like that.

I am not sure how an alternative system could ever be usefully cheaper, so i am not sure what people mean on that front. Even a large pressurised tank isnt mega expensive.

Adam · 3 Feb 2017 at 16:50

I've just been through this same process with the same size house and same issues you had. The old boiler had been there for about 18 years, had definately done it's job well but a consequence was that the 2nd shower we had trickled water. You could not have a shower.

In the end we got a Worcester Bosch 18ri, Worcester Bosch SC-210 cylinder as well as a Nest for the controls. All in including fitting, a magnetic filter etc was just under £4k.

We can now use both showers although the pressure dips due to a poor cold mains feed.

Buffman · 3 Feb 2017 at 18:11

Jez said:
I just got a pressurised system commissioned literally today. Utterly amazing and really wish i had done it sooner. To have mains pressure hot water is something i would always immediately fit to any house i were to live in now. The showers all run at the same time happily, and are as powerful as i have ever experienced in any upmarket hotel or anywhere like that.

I am not sure how an alternative system could ever be usefully cheaper, so i am not sure what people mean on that front. Even a large pressurised tank isnt mega expensive.

I assume you have more than one shower?

I have a new combi and the pressure in my one shower is fine. Tbh I think I would even keep it if I had two showers (as its unlikely to have 2 showers at the exact same time?)

Jez · 3 Feb 2017 at 19:18

We found that virtually every morning we were having to ask each other what time we were going in the shower and work out getting up over that, so it's not very unusual to want to get up at the same time I wouldn't say?

Our son will get to the age where he showers within the next few years too, so that could be three at once in theory.

I think it just depends on the size of the house really, and also if you are prepared to put up with the bulk of a large pressure tank - it's pretty colossal with all of the ancillarie and of course you need a boiler somewhere else in top of that

Adam · 3 Feb 2017 at 19:58

You need to consider the size of the water main entering the house. Ours is quite small apparently so you can't have 2 showers at the same time as the pressure drops due to the cold water (hot is fine).

Buffman · 3 Feb 2017 at 20:24

Adam said:
You need to consider the size of the water main entering the house. Ours is quite small apparently so you can't have 2 showers at the same time as the pressure drops due to the cold water (hot is fine).

Could just have a cold water feed tank on the electric shower and one boiler fed shower.

(saves you heating a tank in the loft which will constantly lose heat). Depends on the quality of your house I suppose!

Freefaller · 3 Feb 2017 at 23:06

Can you not get an electric shower? They don't need a hot water feed and they usually have pretty good pressure as they are fed off the mains no? (Well, ours does at any rate!)

Participant · 4 Feb 2017 at 07:46

We had a combi that we replaced with an unvented ('high pressure') system and it's just the best option (of those mentioned) for a family. Stored high pressure balanced hot and cold at every outlet in the house and since it's effectively powered from the water main, it'll still work if there's a power cut.

We also upgraded our 15mm cold water copper main to 32mm MDPE (blagged under lead replacement even though ours wasn't lead!). At over 4 bar static for our supply, this gives a flow rate of some 50L per minute. We can run showers and baths simultaneously at great flow rates. Dynamic pressure is 1.8 bar, so akin to a 2 bar shower pump even when all outlets are running simultaneously.

We've got a Worcester Bosch system boiler and 300L cylinder, controlled by the Worcester Wave system.

We stuck ours in the garage:

Other points from things people have said in this thread:

- Avoid electric showers if you in any way value a luxury showering experience. Spending £10k on upgrading your bathroom / ensuite then sticking a crappy electric shower in is madness. Even the 10.5Kw ones are useless compared to unvented, pumped, and even combi.

- I don't get how the op's flow problems have only now materialised since he's had the bathroom done. Did the plumber fit the correct type of shower? Did the plumber not advise on your pressure / flow / showering options at the outset of the job? If he'd have fitted a pump as part of the job it would have made much more sense.

- What size are op's hot and cold tanks? Pumping lots of water from a small tank will mean you're rushing your showers. Not fun.

- Combi will disappoint you with four people. As water demands grow you'll find that only one of you will be able to shower at once in the morning. This gets boring very quickly. However unvented will perform poorly if your incoming water main is low pressure / flow; same goes for your internal plumbing.

Matt_Hirst · 4 Feb 2017 at 09:48

To answer the questions, the plumber who did the work mentioned fitting a pump if needed, do bathroom first and see what we think.

The tank in airing cupboard is a tank, about half height of the pressurised one but I would say wider.

Previously shower flow rate was ok, unless you ran something else at same time.

I think I'm leaning towards pressurised tank, so will make some more enquiries on that option.

Matt

a1ex2001 · 4 Feb 2017 at 10:45

Matt_Hirst said:
To answer the questions, the plumber who did the work mentioned fitting a pump if needed, do bathroom first and see what we think.

The tank in airing cupboard is a tank, about half height of the pressurised one but I would say wider.

Previously shower flow rate was ok, unless you ran something else at same time.

I think I'm leaning towards pressurised tank, so will make some more enquiries on that option.

Matt

If you have the fpacd and budget pressurised tank is the way to go!

Participant · 4 Feb 2017 at 10:52

Matt_Hirst said:
The tank in airing cupboard is a tank, about half height of the pressurised one but I would say wider.

Half the height of what pressurised one? You also need to check your cold tank is big enough or you'll get starvation, as it'll drain it faster than it'll refill it.

As I said it's critical you measure your mains flow and pressure (dynamic and static) before going for unvented. If your main is poor, the unvented system will be poor since the pressure and flow to the entire house is fundamentally determined by the quality of the supply with a pressurised system.

Everything after your incoming mains can be fixed / upgraded; not so easy if the incoming is only 1.5bar.

a1ex2001 said:
If you have the fpacd

The what?

Freefaller · 4 Feb 2017 at 13:26

I personally would avoid pumps, my parents have one and it is noisy - it is amazing though, but I couldn't deal with the noise.

I'm interested in this thread as I do want to do a boiler upgrade at home. We have a standard heat only boiler, and a hot water tank - but we have electric showers (which personally I find great (they're powerful I guess because we have decent water pressure)), but I'm not sure whether to go for a combi (we seldom have baths, and we have electric showers), it would free up having a hot water tank in the cupboard.

The house has a lot of old pipework so I don't know whether or not a pressurised system would work - I guess when we do our extension work we could redo all the pipework.

Interesting thread

Matt_Hirst · 4 Feb 2017 at 15:49

Participant said:
Half the height of what pressurised one? You also need to check your cold tank is big enough or you'll get starvation, as it'll drain it faster than it'll refill it.

As I said it's critical you measure your mains flow and pressure (dynamic and static) before going for unvented. If your main is poor, the unvented system will be poor since the pressure and flow to the entire house is fundamentally determined by the quality of the supply with a pressurised system.

Everything after your incoming mains can be fixed / upgraded; not so easy if the incoming is only 1.5bar.

The what?

Half height of the one in the picture in the thread.

Got a large cold water tank in the loft at the moment and minute header tank in there as well for heating I think.

Matt

a1ex2001 · 4 Feb 2017 at 19:14

Participant said:
Half the height of what pressurised one? You also need to check your cold tank is big enough or you'll get starvation, as it'll drain it faster than it'll refill it.

As I said it's critical you measure your mains flow and pressure (dynamic and static) before going for unvented. If your main is poor, the unvented system will be poor since the pressure and flow to the entire house is fundamentally determined by the quality of the supply with a pressurised system.

Everything after your incoming mains can be fixed / upgraded; not so easy if the incoming is only 1.5bar.

The what?

Epic fat fingers moment should say space!