Gavity fed/ pump shower All aspects of plumbing questions and answers, help, tips and information

[johnny1001]

I am installing a new shower, I have stuart tuner duel pump 2.6 bar a mira thermastatic shower at the moment the system is gravity fed with a cold water in the roof and hot cylinder on first floor level. What I would like to know is: Do I need a separate hot feed or can I use the existing 22mm bath/wash basin. I have a 15mm cold to the shower. Thanks Johnny.

[rosebery]

You need a separate hot feed from the HWC. Fit a Surrey, Warix or E s s e x flange (whichever is most appropriate to your installation) and pipe so that this feeds the hot side of the pump. Does the 15mm feed to the shower come from the CWST in the roof? If not it should via the cold side of the pump.

Cheers

[johnny1001]

Hi Rosebery
Thanks for your reply, Can I Tee of from the 22mm pipe at the top of the hw cylider reduce to 15mm to the hot side of the pump? The 15mm feed does come from the CWST in the roof so thats no problem. Johnny.

[rosebery]

"Can I Tee of from the 22mm pipe at the top of the hw cylinder reduce to 15mm to the hot side of the pump?"

Only if a) you alter the vent so that having risen a short distance it is then angled out at approx 45 degrees for a couple of feet then is returned to the vertical - tee off the angled pipework and b) your pump is able (see the MIs) to operate with this piping arrangement. If you try and tee straight off the vent as you describe you'll be back on here in a couple of weeks (or less) asking why the shower doesn't work properly and the pump howls like a banshee. The anser to both questions will be that its sucking a mixture of air down the vent and water up from the tank.

Far easier to fit a Surrey or Warix flange in the top of the tank so that you get separate feeds for shower and taps. Both will give you a 15mm outlet for the hot for the pump.


"The 15mm feed does come from the CWST in the roof so thats no problem."

OK good - if it were mains you'd a) have unbalanced supplies and b) a non-conforming installation because you are not allowed to pump mains. Oh and it is a new connection to the tank completely separate from other cold services isn't it? If not make it so.

Cheers

[chris_on_tour2002]

" Can I Tee of from the 22mm pipe at the top of the hw cylider...?"

no you can't. you need to run a separate feed from the cylinder via one of the flanges already specified by rosebery. the 22mm pipe coming from the top of your cylinder is supplying DHW around the house so if you tee into that the pump will suck water away from the rest of the house, or the pump may be starved of water and start sucking in air.

"The 15mm feed does come from the CWST in the roof so thats no problem" - or is it? you may want to double check, it might not come FROM the CWST, it may be going TO it as the cold main feed. check that it is actually connected to the base of the tank, not the ballcock. but again it's of little relevance as you will want to run a dedicated feed on the cold side from the tank to the pump anyway.

good luck!

[johnny1001]

Thanks rosebery & chris_on_tour2002
Is it easy to fit a surrey, warix or ******* flange and how do I go about it, as I have not fitted one before I have a fully lagged HW Cylinder. About 180mm / 7 inches from the top of the Cylinder is capped off 22mm outlet, could this be an alternative connection for the hot side of the pump / shower? The physical size of the cylinder is 1070mm / 42 inches X 460mm / 18 inches.
I have checked the cold supply and it does come directly from the bottom of the CW Tank in the roof so that's OK. Johnny.

[rosebery]

Surrey and Warix fit in the top of the tank where the hot feed to taps comes out and continues vertically to the vent. Shorten the vertical pipe to accommodate. They have a horizontal takeoff in 15mm for the shower feed. A Warix has the advantage that it can be adjusted so that the 15mm takeoff is rotated to line up with the shower pump feed pipe. A Surrey cannot.

Lol if you type E s s e x without spaces the forum censor software kicks in and it comes out as Deleted as in your post. The 22mm tapping you speak about on the side of the cylinder wil do fine for fitting an E s s e x flange. Some say its the best way of connecting aseparet feed for the shower. You are lucky that you have a boss available to connect to. Where there isn't one it means cutting a hole in the cylinder if an E s s e x is required and thats not a job for the fainthearted or inexperienced 'cos its sooo easy to damage the tank.

Use your search engine to find details of fitting of each.

OK about the cold so long as its a SEPARATE pipe from other cold services. IE it shouldn't be teed off another pipe.

Cheers

[johnny1001]

Hi Rosebery,
Thanks for coming back so prompted, As I have a 22mm at the side off the cylinder I will use it, Just thought that being 7 inches down the side will I get the full amount of hot, will it also pull hot water from between the 7 inch outlet and the top of the cylinder or will just pull hot water from below. As you say cutting holes in copper cylinders might be a little tricky, I have ordered everything for my shower and is sitting in my garage except for the shower screen which will be delivered mid January, Then I can get started, Great. Thanks, Johnny.

[rosebery]

You'll be OK. Don't forget that as the hot water is drawn off the top of the cylinder its replenished at the bottom from the CWST. BTW what size is you CWST? Should be iro 50 gallon for this application or you'll empty it too quickly.

Cheers

[johnny1001]

Hi Rosebery,
Just been up in the roof to measure my cold water tank it is a round plastic one and measures 83cm /33 inches X 61cm / 24 inches tall, I think this about a 50 gallon tank.
Thanks again for all your help much appreciated and if you are ever in Cornwall drop in and have a shower. Many thanks, Johnny.

[rosebery]

No worries. Good luck with it.

Cheers