Hot water for Showers in a HMO (Shared House)

[JohnP2500]

Hi All,

I am part way though converting a property into a House of Multiple Occupation. It will have 6 bedrooms (and six showers). It's my 1st conversion of this size so I have made a couple of school boy errors!

I had new GCH installed last year (Glow worm 30c). This provides heating and hot water to taps only.

Originally I planned to have 4 Electric showers and run 2 from the boiler.

At the moment I have finished 3 rooms, they have electric showers. The electrician is not keen to install a fourth electric shower. When the boiler was installed it was mentioned that the pressure was crap (not sure what it is) the flow is about 1o litres/Min.

In retrospect I should have increased the incoming main size (it's 15mm). It would be a right pain to do it now.

So the question is what to install to provide hot water for the 3 remaining showers. I have heard a lot about Mega Flow systems, but these don't seem to increase pressure?

Could I run the 3 showers from the boiler? (it's unlikely 3 people would shower at once)
Do I install one large water heater or 3 smaller ones?

Obviously I will be getting quotes and getting all work done professionally but I am struggling to know what to get quotes for?

I'm in Torquay so if anyone is interested in the work let me know. Thanks John

 

[dancinplumba]

Anyone near Torquay ? there are solutions, the installer should suggest what to install

 

[New Gas Engineer]

I wonder why your sparky doesnt want to install a 4th electric shower.

 

[SimonG]

Pushing it with 2. Once installed 2 in one house, sparky used a relay to ensure only 1 could be used at once.

Watts = Amps x Volts

So 4 x 10.8kw showers equates to 43,200 ÷ 230 = 188 amps. Normal supply is 100 amps.

Don't forget lights, tv, fridge, freezer etc etc.

 

[ShaunCorbs]

not a hope in hell

time to upgrade the mains or fit a break tank and pump

 

[JohnP2500]

Pushing it with 2. Once installed 2 in one house, sparky used a relay to ensure only 1 could be used at once.

Watts = Amps x Volts

So 4 x 10.8kw showers equates to 43,200 ÷ 230 = 188 amps. Normal supply is 100 amps.

Don't forget lights, tv, fridge, freezer etc etc.

I've only got 8.5kw showers. Then relying on divergence? aka fingers crossed they don't all shower at once!

 

[ShaunCorbs]

I've only got 8.5kw showers. Then relying on divergence? aka fingers crossed they don't all shower at once!

theres still about 140 amps you would need 3 phase power

 

[JohnP2500]

not a hope in hell

time to upgrade the mains or fit a break tank and pump

Is a break tank the same as an accumulator?

 

[ShaunCorbs]

Is a break tank the same as an accumulator?

no why do you ask has he suggested fitting one?

 

[SimonG]

Try explaining pot luck to national grid when you keep popping the main fuse.

 

[ShaunCorbs]

Try explaining pot luck to national grid when you keep popping the main fuse.

a m20 bolt should sort that out 😀

 

[JohnP2500]

no why do you ask has he suggested fitting one?

No, I'm trying to get an idea of possible solutions and had seen that an accumulator may be a solution?

 

[ShaunCorbs]

No, I'm trying to get an idea of possible solutions and had seen that an accumulator may be a solution?

whats the internal pipework dia?

 

[JohnP2500]

whats the internal pipework dia?

It's all new 15mm.

 

[ShaunCorbs]

It's all new 15mm.

accumulator wont help as your issue is your internal pipework flow capacity, sorry to say only decent way that will work is repipe

 

[JohnP2500]

accumulator wont help as your issue is your internal pipework flow capacity, sorry to say only decent way that will work is repipe

The incoming main is 15mm. So far the ground floor is complete and no complaints from tenants about pressure. The next stage is loft room and 1st floor. Could an accumulator just serve these 3 rooms? If it was re-piped would that be 22mm with 15 teeing to rooms? Thanks

 

[ShaunCorbs]

The incoming main is 15mm. So far the ground floor is complete and no complaints from tenants about pressure. The next stage is loft room and 1st floor. Could an accumulator just serve these 3 rooms? If it was re-piped would that be 22mm with 15 teeing to rooms? Thanks

Have they been used all at the same time eg full

And I could but it's bigger than a cylinder

 

[chris watkins]

There are school boy errors & then there is got no idea what I am doing, I think this is the latter.
Sorry if that sounds harsh but come on you are half way through a six shower (we will forget the rest of the water usage) installation before it occurs to you that a 15mm incoming mains water supply is not good enough.
Ever heard of leaking professional advice rather than diy.
You are not getting advice free from me!!

 

[Scott_D]

Did you know this was the plan when you had the combi installed?

 

[king of pipes]

Time for a repipe , I would consider adding another boiler and a 300 litre unvented cylinder with a secondary return , Mira showers with flow restricted to 8 litres a minute dump the electric shower idea . Kop

 

[Murdoch]

I've only got 8.5kw showers. Then relying on divergence? aka fingers crossed they don't all shower at once!

Your spark won't install a 4th

Matey - 3 is too many ......... so I'd recommend you get a new spark too - or is this DIY too?

Who's doing the alarm systems?

 

[Welder]

Tbh. The whole things a shower. MO props never do it right cos its all about the ££.

OP. If you wish to do it prop, i.e. not suffer complaints for the rest of eternity, just bite the bullet, get mains upgraded and get pro advice.

 

[Ric2013]

10l per minute is pretty poor even for a 15mm main.