Dose a Combi boiler work well for showers?

LocoLogo · 16-09-2020 11:12pm #1

Im doing a reno on a 1970s 3 bed house (1 bath/shower room and 1 en suite with a shower). Rather than spending a fortune on an air to heat system im considering other options i.e. getting a Combi boiler. The house dose not have a cylinder or hot water tank. I

Im looking for a system where I can get decent shower pressure instead of using electric showers? wondering if the combi systems would work well for shower pressure or would i need a pump tank etc to go along with it?

[Deleted User] · 16-09-2020 11:16pm

my experience was it delivered a very weak supply of hot water for showering or a bath

fine for washing up

maybe that was a water pressure issue, not sure

Ush1 · 17-09-2020 8:39am

You don't need a hot water tank but does the house not have a cold water storage tank?

That's what I have with my combi and a pump and the pressure is good.

Calahonda52 · 17-09-2020 11:27am

Ush1 wrote: »

You don't need a hot water tank but does the house not have a cold water storage tank?

That's what I have with my combi and a pump and the pressure is good.

which side of the boiler is the pump?

Ush1 · 17-09-2020 3:18pm

Calahonda52 wrote: »

which side of the boiler is the pump?

Cold water tank feeds the pump which pushes water through combi and gets heated.

LocoLogo · 17-09-2020 4:23pm

I believe there is but I understood the boiler would be fed off the main?

What type of shower are you using? electric or regular type

jmBuildExt · 18-09-2020 11:57am

I have a combi boiler with a single shower running off it (normal non-powered thermostatic mixer valve). We also have the taps at 4 sinks - and even the toilet is fed from the pump associated with it.

I'm not actually sure which side of the boiler the pump is. I'd kind of assumed it was after the boiler but i have no basis for that assumption now i think about it.
Edit - either way its ultimately fed from the cold water tank in the attic.

Anyway - the pressure and water delivery is good in the shower, actually very good in my experience with showers (shower has a big rainwater head, shower upstairs, pump downstairs) - But it drops a bit if someone e.g. runs the hot tap full blast down in the kitchen. But we have the pump on setting 2 of 5 - maybe that would improve if it was upped - but in saying that it hasn't caused me too many problems that i'd want to up it.

The pump is noisy - keep it out of your house (e.g. in a garage) if possible. And insist on it being placed on concrete if it has to go inside. You can also get damper mats.

Mine is in my kitchen on a suspended floor! Its far enough away from where we sit and watch TV (down the other end of the extension), and you cant hear it in the sitting room or upstairs - so the noise doesn't bother us too much. But if you're close to it - its a bit of a nuisance if you're talking or whatever.

Calahonda52 · 18-09-2020 5:24pm

LocoLogo wrote: »

I believe there is but I understood the boiler would be fed off the main?

What type of shower are you using? electric or regular type

You cant feed the boiler off the mains, its against the regs and also dangerous

Sesame · 19-09-2020 7:12pm

Calahonda52 wrote: »

You cant feed the boiler off the mains, its against the regs and also dangerous

How is it dangerous?

salmocab · 19-09-2020 7:15pm

Our showers are off the combi, no pumps and they are grand. Only downside is only one shower at a time and having to wait a few extra seconds for the hot water. Well worth the pay off for not having an immersion.

LocoLogo · 19-09-2020 7:53pm

salmocab wrote: »

Our showers are off the combi, no pumps and they are grand. Only downside is only one shower at a time and having to wait a few extra seconds for the hot water. Well worth the pay off for not having an immersion.

Are you using electric showers? do you have a pump installed to help with the pressure?

bobbyy gee · 19-09-2020 7:56pm

Get your cold water tank up high on the attic or you get low water pressure

salmocab · 19-09-2020 8:30pm

LocoLogo wrote: »

Are you using electric showers? do you have a pump installed to help with the pressure?

No just mixer valves, it’s just mains pressure, we actually took out a pump when we removed the hot tank. Had the en-suite done up this year and put in a rain shower head, the plumber said he didn’t think it would have enough pressure but it’s fine.

[Deleted User] · 20-09-2020 2:36pm

I built an extension about 3 years ago. Part of it was gonna have a bathroom (toilet/shower/sink). I wanted a Combi Boiler, as i wanted rid of the hot-tank (took up too much space, and i needed a new boiler anyway). Our combi boiler is fed straight from the mains, and has no pumps or such, we also don't have an electric shower (thermostatic mixer shower panel).

Our entire house is pretty much off the mains now, with the exception of an upstairs toilet that still utilises the cold water tank (as far as I can recall). We have issues with water pressure if there are several outlets turned on, as the pressure is shared (ie; getting a shower and washing the delf at the same time leads to both users getting half the pressure).

In terms of pressure itself, when no one else is using the water, the shower can seem like something the riot police would use on you. It's great. Even with the pressure split in two, it's entirely usable. It does suffer a good bit if a third user appears, but that's extremely rare in my house (I actually can't think of a time it ever happened in day-to-day life, except when I was deliberately testing it out).

I'd highly recommend a Combi boiler. That said, I live in a house estate where our water services/pressure are generally top notch (barring some limescale issues). If you live in Rural Leitrim you may have more difficulty perhaps.

Calahonda52 wrote: »

You cant feed the boiler off the mains, its against the regs and also dangerous

I have heard that a few times (on Boards) but I don't think it's entirely true. I had two plumbers working on my extension, and both were going to do it that way (first fella kept no-showing so I replaced him). I was getting a boiler grant, so the work was inspected twice by SEAI (failed first time for a leaking radiator and a boiler flue incorrectly placed). Two different SEAI inspectors, and neither mentioned or cared about it being connected to the mains.

mad m · 20-09-2020 3:59pm

Calahonda52 wrote: »

You cant feed the boiler off the mains, its against the regs and also dangerous

What regulations? Also how is it dangerous?

Sesame · 22-09-2020 10:56am

Deleted User wrote: »

I have heard that a few times (on Boards) but I don't think it's entirely true. I had two plumbers working on my extension, and both were going to do it that way (first fella kept no-showing so I replaced him). I was getting a boiler grant, so the work was inspected twice by SEAI (failed first time for a leaking radiator and a boiler flue incorrectly placed). Two different SEAI inspectors, and neither mentioned or cared about it being connected to the mains.

I had exactly the same on a previous house. Worked off mains and I got a SEAI grant with a double inspection (one of which was an audit of the inspection) which it passed. The attic tank and immersion tanks removed. Shower was amazing. It was mains water, not a well and the plumber did some pressure checks initially to check if it would be suitable for a good shower and if not, he was going to do something with a pressurised system but didn't need to.
Combi boilers are under rated in Ireland. There are very few cons in my opinion and are efficient in that they only heat the water you use and don't heat a big immersion tank of water each time that you have to wait for. :pac:

If it really was dangerous to run off mains, wouldn't someone the registered plumber or inspectors at some point have mentioned it or not done it?

Calahonda52 · 22-09-2020 12:45pm

Have the installations got non return valves and pressure reduction vales on the incoming mains?
as to whats right, lets see what they say
https://www.boards.ie/ttfthread/2058115585

[Deleted User] · 22-09-2020 1:56pm

Calahonda52 wrote: »

Have the installations got non return valves and pressure reduction vales on the incoming mains?
as to whats right, lets see what they say
https://www.boards.ie/ttfthread/2058115585

Maybe I'm the clueless one, but it doesn't really seem like IW answered you there. More of a shoulder shrug than a definitive answer (from my perspective?).

Calahonda52 · 22-09-2020 2:43pm

Deleted User wrote: »

Maybe I'm the clueless one, but it doesn't really seem like IW answered you there. More of a shoulder shrug than a definitive answer (from my perspective?).

Yeah, they don't seem care what happens inside the property line, which seems strange, given that they can easily, when doing repairs, create neg pressure on the domestic feed, thereby sucking hot water from the combi into the mains and the other scenario is all the muck that comes with repairs.

Next stop SEAI: zzzzZ:D

[Deleted User] · 22-09-2020 3:37pm

Calahonda52 wrote: »

Yeah, they don't seem care what happens inside the property line, which seems strange, given that they can easily, when doing repairs, create neg pressure on the domestic feed, thereby sucking hot water from the combi into the mains and the other scenario is all the muck that comes with repairs.

Next stop SEAI: zzzzZ:D

I presume you'll get the same reply again off SEAI. Perhaps local council would be the ones to ask?

salmocab · 22-09-2020 3:44pm

Surely asking in the plumbing thread is the way to go?

Lumen · 23-09-2020 7:23am

I always assumed that the reason mains connection isn't allowed is so that the LA/IW can muck around with water pressure without getting claims off people for damaged equipment or poor service.

Other countries manage this fine.

Calahonda52 · 23-09-2020 7:32am

Deleted User wrote: »

I presume you'll get the same reply again off SEAI. Perhaps local council would be the ones to ask?

So the deal seems to be that only Dublin city council has it explicit in it's bye laws, no other LA has it.
The only case where it might be an issue with SEAI inspections is for grants under the BEH scheme.
As the the why I didn't bother asking.
This implies nothing in the TGDs.
Case closed, I wont mention it again:D:D

brisan · 25-09-2020 3:46pm

Calahonda52 wrote: »

You cant feed the boiler off the mains, its against the regs and also dangerous

How do they manage in apartments with combi boilers and no cold water tank or hot water tank
Asking for a friend

salmocab · 25-09-2020 4:05pm

brisan wrote: »

How do they manage in apartments with combi boilers and no cold water tank or hot water tank
Asking for a friend

Apartments would generally have a Communal water tank feeding each unit

Dose a Combi boiler work well for showers?

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