Ensuite loft conversion, plumbing options

[xr4x4]

Hi all,

I'm getting involved in a loft conversion next year and I'm thinking about options for the on suite shower room.

3 bed, 1 bathroom, 1 on suite house around 3 years old and currently has a vented cylinde and cws in the loft.

En suite had gravity shower, I fitted twin positive pump in airing cupboard. Also fully fitted aqualisa digital pumped shower in bathroom, unit in loft.

Now for loft conversion stairs are going in airing cupboard, so cylinder has to be moved, I think to cupboard next door.

What are my options for toliet, basin and shower in en suite for loft conversion? Customer hasn't got budget for vented cylinder.

I was thinking mains water for toliet, then maybe a negative pump for sink hot and cold and shower but I'm worried about the noise everything someone opens the tap.

A coffin tank will be installed but I'm not sure much height will beable to be gained to use gravilty alone.

Any thoughts?

 

[xr4x4]

Any thoughts?

Was thinking hot water pump and mains cold to shower and sink?

 

[GavThePlumber]

If they have the pressure, then they are quite simply idiots for not putting in an unvented cylinder.

 

[xr4x4]

That's not in the budget.

So as well as buying a unvented cylinder, paying someone with a g3 ticket to install it and buying a new auqalisa digital processor.

Not as simple as installing a hot water pump but I've never installed one and don't know what the implications are, will the whole house hot water have to be pumped? Or can the leg up to the loft just be pumped?

 

[GavThePlumber]

It is much more cost effective, get in another plumber for a quote.

 

[xr4x4]

It is much more cost effective, get in another plumber for a quote.

I am the plumber..lol

 

[Madrab]

If un-vented not an option then mains to all cold and negative head pump on dedicated feed from the cylinder for the hot, just for the loft, is really the only option.
You will have the issue with pump noise, can't get away from it unless you can get the CW tank up over a metre above, even if the pressure would be pants.
You will have to balance the shower mains cold feed to within 1/2 a bar of the pump as well
Have to consider the cylinder capacity as well, if 3 pumped showers (bathroom/en-suite/loft?) could be drawing at the same time.

 

[xr4x4]

If un-vented not an option then mains to all cold and negative head pump on dedicated feed from the cylinder for the hot, just for the loft, is really the only option.
You will have the issue with pump noise, can't get away from it unless you can get the CW tank up over a metre above, even if the pressure would be pants.
You will have to balance the shower mains cold feed to within 1/2 a bar of the pump as well
Have to consider the cylinder capacity as well, if 3 pumped showers (bathroom/en-suite/loft?) could be drawing at the same time.

Thanks for that, that's kinda the way of thinking I was going.

The room will be for one of the kids, so late night showers not a problem, as regards noise.

Will need to speak to customer about the noise of the pump, then it's up to them.

Will install a PRV on cold to balance as much as possible to match the pump, 2 bar most likely.

Will a nrv in the hot feed be needed to stop it interfering with the rest of the house?

 

[Dean744PiN5]

What ever you do, don't fit a salamander whole house pump it's a noisy fooker, especially if toilets flushed at night.

 

[xr4x4]

What ever you do, don't fit a salamander whole house pump it's a noisy fooker, especially if toilets flushed at night.

Thanks,

Pump will only be on hot and only for hot tap and hot for shower in loft conversion, rest will be mains cold.

 

[Madrab]

I'm a bit confused Paul, you 1st post said

En suite had gravity shower, I fitted twin positive pump in airing cupboard. Also fully fitted aqualisa digital pumped shower in bathroom, unit in loft.

Then you said

Not as simple as installing a hot water pump but I've never installed one and don't know what the implications are, will the whole house hot water have to be pumped? Or can the leg up to the loft just be pumped

Fitting a hot pump is exactly the same as a twin pump, well a twin pump is both hot and cold whereas a single pump would be either hot or cold but they work exactly the same way??

That would mean that you will have 2 pumps in by the cylinder, the twin one and then this new hot one? The hot one shouldn't make any more noise than the twin already there so they should be used to it, unless they do run at the same time, then it'll be like concorde taking off

A check valve wouldn't really be needed on the new pumped hot side as it's not mains fed but if using body mixer taps then strictly speaking all hot mixer feeds should have at least a single check valve, shower will probably come with nrv's. The new pump will need it's own feed from the cylinder though, where I guess one already exists for the twin pump? So if there's a surrey in there you'd need an essex. I wouldn't use the same feed as the twin just in case the hot water is used at the same time as downstairs. BTW, where does the Aqualisa get it's hot feed from, just the normal hot feed?
Oh and the new pump will need a new radial or spur to feed it, don't be tempted to wire into the one that the other twin pump is currently using. If taking a feed for the new FCU from the current one check it's a radial circuit and not already a spur from the ring final (big no no) and the MCB is suitable.

 

[xr4x4]

I'm a bit confused Paul, you 1st post said

En suite had gravity shower, I fitted twin positive pump in airing cupboard. Also fully fitted aqualisa digital pumped shower in bathroom, unit in loft.

Then you said

Not as simple as installing a hot water pump but I've never installed one and don't know what the implications are, will the whole house hot water have to be pumped? Or can the leg up to the loft just be pumped

Fitting a hot pump is exactly the same as a twin pump, well a twin pump is both hot and cold whereas a single pump would be either hot or cold but they work exactly the same way??

That would mean that you will have 2 pumps in by the cylinder, the twin one and then this new hot one? The hot one shouldn't make any more noise than the twin already there so they should be used to it, unless they do run at the same time, then it'll be like concorde taking off

A check valve wouldn't really be needed on the new pumped hot side as it's not mains fed but if using body mixer taps then strictly speaking all hot mixer feeds should have at least a single check valve, shower will probably come with nrv's. The new pump will need it's own feed from the cylinder though, where I guess one already exists for the twin pump? So if there's a surrey in there you'd need an essex. I wouldn't use the same feed as the twin just in case the hot water is used at the same time as downstairs. BTW, where does the Aqualisa get it's hot feed from, just the normal hot feed?
Oh and the new pump will need a new radial or spur to feed it, don't be tempted to wire into the one that the other twin pump is currently using. If taking a feed for the new FCU from the current one check it's a radial circuit and not already a spur from the ring final (big no no) and the MCB is suitable.

I was just worried about the balancing issue on the shower, with mains cold.

I was also unsure if the pump could pump above the tank.

I'm fine now!