Shower(s) and hot water supply

[Pocster]

1 minute ago, Nickfromwales said:

Need to know as it'll be heating the system. 

If it's only a 24/28kw then we may end up going W-plan aka "DHW priority" where it doesn't do space heating and hot water together and any time the hot water needs topping up the system will divert from heating to do so by design.

The hot out of the combi will just do the kitchen sink so it ( the moving hot water components etc ) stays active, with the heating output serving the rads and UVC via the W-plan arrangement. 

Controls can be discussed on a separate thread if you like, when a system is firmly decided upon. 

Ok !

ill need to go to the property and get the model number - suspect 24/28kw 

[Ferdinand]

25 minutes ago, pocster said:

Ok !

ill need to go to the property and get the model number - suspect 24/28kw 

 

If it is a rental your gas safety certificate will tell you.

 

There may be a facility at the Gas Safety Register website to check by address, but I am not sure.

[Nickfromwales]

Ok, next up is available plant space and some plans maybe?

 

On 01/04/2018 at 16:00, pocster said:

Dont want any chance of flow dropping due to multiple showers in use

The flow will naturally reduce with demand, but if the restrictors are selected properly you won't be stealing all of the available flow. You need to give ADEQUATE flow to each shower to guarantee results, OR you fit a second accumulator. A Zimlet 500L will set you back a bit less than £600 iirc but you can check on the PumpsUkLtd website under accessories. That'll give you dimensions too if you look under downloads on the same page. 

FYI, running 5 showers and still having a bit of oomph for other outlets is nigh-on commercial territory, so dont expect to do this on a shoe-string budget, it'll need some moola throwing at it. 

FWIW I would ditch the notion of the single electric shower and go all mixers. Instead, used the immersions ( 4 x 3kw in a 500 is possible if ordering bespoke ) as your failsafe, so you'll still have DHW even if the boiler goes down. Pointless in just having one working failsafe electric shower unless its in a communal bathroom ( if the 5 showers are all ensuite then no-one is going to want to share the only working shower with 4 others ).

The sparky will have to be on board with this design too, so involve them as early on in the process as possible.    

[Pocster]

5 hours ago, Nickfromwales said:

Ok, next up is available plant space and some plans maybe?

 

The flow will naturally reduce with demand, but if the restrictors are selected properly you won't be stealing all of the available flow. You need to give ADEQUATE flow to each shower to guarantee results, OR you fit a second accumulator. A Zimlet 500L will set you back a bit less than £600 iirc but you can check on the PumpsUkLtd website under accessories. That'll give you dimensions too if you look under downloads on the same page. 

FYI, running 5 showers and still having a bit of oomph for other outlets is nigh-on commercial territory, so dont expect to do this on a shoe-string budget, it'll need some moola throwing at it. 

FWIW I would ditch the notion of the single electric shower and go all mixers. Instead, used the immersions ( 4 x 3kw in a 500 is possible if ordering bespoke ) as your failsafe, so you'll still have DHW even if the boiler goes down. Pointless in just having one working failsafe electric shower unless its in a communal bathroom ( if the 5 showers are all ensuite then no-one is going to want to share the only working shower with 4 others ).

The sparky will have to be on board with this design too, so involve them as early on in the process as possible.    

Boiler info:

 

Vailiant ETECPRO28

 

I thought the 1 electric working if the UVC bust is better than nothing. At least *a* shower is possible.

I also thought that the electric takes the strain of the UVC - i.e. it only has to deal with 4 showers potentially on simultaneously 

 

cheers

[Nickfromwales]

 If it's only a 28kw then we may end up going W-plan aka "DHW priority" where it doesn't do space heating and hot water together, so any time the hot water needs topping up the system will divert from heating to do so, by design.

The 28kw gives around 25Kw to heating ( or heating / hot water in your case ) so going Y or S plan ( space heating and DHW reheat simultaneously) is a bit ambitious from 25Kw for a cylinder that big. You really should be taking the combi out and be fitting a correctly sized system boiler TBH. 

The hot out of the combi could just do the kitchen sink so it ( the moving hot water components etc ) stays active, with the heating output serving the rads and UVC via the W-plan arrangement. 

Controls can be discussed on a separate thread if you like, when a system is firmly decided upon.

1 hour ago, pocster said:

I thought the 1 electric working if the UVC bust is better than nothing. At least *a* shower is possible.

I also thought that the electric takes the strain of the UVC - i.e. it only has to deal with 4 showers potentially on simultaneously 

The uvc won't typically 'go down', the most likely failure will be the boiler or motorised valves. 

Are all the showers ensuite? 

[Pocster]

1 minute ago, Nickfromwales said:

 If it's only a 28kw then we may end up going W-plan aka "DHW priority" where it doesn't do space heating and hot water together, so any time the hot water needs topping up the system will divert from heating to do so, by design.

The 28kw gives around 25Kw to heating ( or heating / hot water in your case ) so going Y or S plan ( space heating and DHW reheat simultaneously) is a bit ambitious from 25Kw for a cylinder that big. You really should be taking the combi out and be fitting a correctly sized system boiler TBH. 

The hot out of the combi could just do the kitchen sink so it ( the moving hot water components etc ) stays active, with the heating output serving the rads and UVC via the W-plan arrangement. 

Controls can be discussed on a separate thread if you like, when a system is firmly decided upon.

The uvc won't typically 'go down', the most likely failure will be the boiler or motorised valves. 

Are all the showers ensuite? 

Yep all showers ensuite.

Boiler was spec'd by an install company that doe the maintenance - can't it just do heating for rads and kitchen tap???

[Nickfromwales]

4 hours ago, pocster said:

Yep all showers ensuite.

Boiler was spec'd by an install company that doe the maintenance - can't it just do heating for rads and kitchen tap???

No lol. 

Itll need to heat the UVC too, unless you have another boiler hidden away ? ?