I'm re-plumbing my power shower, please check my shopping list

[Foxtrot Oscar]

Hi

I've decided to repair a botched shower install myself (long story, but this might give you some idea of it):

(That's the cold feed to the pump you can see top left, the pump is 2 metres away at the end of the bath)

This is the current layout, I am running dedicted 22mm feeds from hot and cold (hot via Essex-style Techflange) and relocating the pump to the airing cupboard:

Here is the list, please could you check it and let me know if I've missed anything obvious?



The previous pump burnt out due to air from the hot vent pipe. I already have spanners and screwdrivers.

Many thanks!

 

[Plumbstar Tom]

are you a DIYer?

why a bending springs and Bender with formers?

will be cheaper to use compression as well I reckon

Also check that the pump can be fitted to bath taps as some cant

 

[Foxtrot Oscar]

Am I a DIYer...not plumbing wise Tom, I've done basic servicing on my car like replacing driveshafts and starter motors! Plumbing-wise all I've done is plumb in a dishwasher with my dad.

Not sure why both bender and bending springs, I figured the springs are so cheap why not get them anyway...could I get away with only a spring for 22mm bends? I only need a few bends.

Compression is a good alternative, I just wanted the most idiot-proof solution as I've had some leaky compression joints in my plumbing career!

Regarding the pump, I'm just plumbing it directly to the shower this time and forgetting powering the bath. This is partly to simplify the pipework and partly because we must use the bath about once every two months, so I'm not paying extra for a 'whole house' pump that is friendly with water going past only one impellor.

Many thanks Tom.

 

[Plumbstar Tom]

Bending springs require more of a 'technique' but im sure Youtube is full of them

Plus numerous bends on 22mm with a spring aint easy on the arms 😀

Good to hear its too the shower only

 

[SimonG]

The only thing I would add is to get the pump in the airing cupboard. Always do this if I can, not always possible, but i prefer it in there.

 

[Foxtrot Oscar]

Thanks Tom, will check YouTube.

The only thing I would add is to get the pump in the airing cupboard. Always do this if I can, not always possible, but i prefer it in there.

Yep, it's going in the airing cupboard as per OP. I'm doing this one by the books, unlike *** Ltd. of Redditch :/.

 

[SimonG]

Missed that bit.

Good luck with it and let us know how you get on

 

[Mikey456]

£17.99 each for a length of 22mm x 2m? Woah, get yourself down plumb center for the pipe.

 

[secret squirrel]

I'd go to a good local plumbing shop. If you get stuck or have any questions you'll find it much easier to speak to a plumber in the local shop as opposed to a muppet in a shed....

If your buying all this stuff you'll get a discount but its the wealth of info you may need because things will probably happen that you haven't counted on.

Also if you get stuck they'll have local tradesmen in who'll probably pop round for a few quid and point you in the right direction. I do this when a diy'er has done his bathroom and just needs the pipes soldering etc.

 

[Foxtrot Oscar]

Just found there's a plumb centre 3 minutes from my house that I had no clue existed! Thanks guys.

Good point about local knowledge, I may be relying on it!

 

[WHPES]

For a start your diagram is wrong. The shower pump needs its own dedicated cold feed from the DHW cistern. Remember that the outlet must be lower than the one for the cylinder (to prevent scalding when water runs low). (Need 22mm tank connector, nylon washers and pipe)

Also you can't take the hot off the main outlet for the cylinder - you need an Essex flange for the cylinder to take a dedicated hot off for the pump. Alternatively you can tee into the horizontal pipe at the top of the cylinder (your tee must be pointing down to prevent dissolved air accumulating in it and airlocking.

You also need 22mm piping at least up to the pump.

The shower instructions should give you details of the system layout required.

See below for corrected version:



Don't forget you need full bore isolation valves in front of the pump for servicing work. Also you cistern must be hygienic with closely fitting lid and byelaw kit.

 

[Foxtrot Oscar]

Many thanks WHPES.

For a start your diagram is wrong.

I think you misunderstood, the diagram illustrates the current situation and the reason that I need to do remedial work in the first place.

The shower pump needs its own dedicated cold feed from the DHW cistern. Remember that the outlet must be lower than the one for the cylinder (to prevent scalding when water runs low). (Need 22mm tank connector, nylon washers and pipe)

Also you can't take the hot off the main outlet for the cylinder - you need an Essex flange for the cylinder to take a dedicated hot off for the pump. Alternatively you can tee into the horizontal pipe at the top of the cylinder (your tee must be pointing down to prevent dissolved air accumulating in it and airlocking.

You also need 22mm piping at least up to the pump.

The shower instructions should give you details of the system layout required.

See below for corrected version:

View attachment 2530

Don't forget you need full bore isolation valves in front of the pump for servicing work. Also you cistern must be hygienic with closely fitting lid and byelaw kit.

Thanks for going to the effort of the amended diagram and for the extra info, it's all being saved in my brain for when I start the job.

One thing I have a question about...the requirement for the feed shower from the cold water tank to be on the opposite side to the rising main input. Thing is, it would be a lot easier for me to position the shower feed as follows:



Is the above acceptable, or should I absolutely position it opposite, no questions? The issue being it will need an immediate elbow, as that side it close to a wall. Which is preferable?

This place is really helping me avoid pitfalls, they're piling up high! Service valve being one I hadn't considered.

 

[WHPES]

I wouldn't worry too much about being on the opposite side, as long as it is lower than the DHW outlet.

Is it possible to put the shower cold outlet in the BASE of the tank?

Look at the MIs for your mixer. Mira usually have really good detailed installation instructions.

Running the feed to the pump in 15mm can sometimes result in cavitation damage which is why for larger pumps 22mm is always stipulated (check with pump MIs)

One thing, if you choose to use an Essex flange, make sure it is really tight as once its on you can't tighetn it up afterwards!

 

[Foxtrot Oscar]

I wouldn't worry too much about being on the opposite side, as long as it is lower than the DHW outlet.

Is it possible to put the shower cold outlet in the BASE of the tank?

Look at the MIs for your mixer. Mira usually have really good detailed installation instructions.

Running the feed to the pump in 15mm can sometimes result in cavitation damage which is why for larger pumps 22mm is always stipulated (check with pump MIs)

One thing, if you choose to use an Essex flange, make sure it is really tight as once its on you can't tighetn it up afterwards!

Gotcha, will make sure it's lower than the hot feed.

The base of the tank would be a mission. Possible, maybe, but a mission and as far as I can see, an unnecessary one.

I'll see if I can find the installation instructions for my shower, if not I'll download it. Thanks.

I'll be running 22mm feeds from hot and cold, as even if I end up with a 1.5 bar pump, I might want to upgrade it down the line and would rather everything was in place.

I don't really get what you say about the Essex flange...why can't I tighten it up once it's on? You can tighten the outer nut alright surely?

 

[WHPES]

Sometimes you can and sometimes the entire thing just spins round! Get a proper Essex branded flange not an inferior copy!

Another point make sure there is enough ventilation round the pump. Sometimes they can overheat when positioned under baths. Is it not possible to put it at the base of the cylinder in the airing cupboard?

Also if you're not likely to use them much I would just use fittings rather than buy a bender and springs. If you are worried about losses in bends you can actually buy slow swept bends as 22mm end feed or solder ring fittings, but personally with 22mm I would just use elbows.

 

[Foxtrot Oscar]

The pump is going in the airing cupboard as per earlier in the thread, we did indeed have problems with the pump overheating. Thermal shutdown would kick in all too often.

Recently found out though that the Grundfos that burnt out was only rated for 20 on 40 off, pathetic when there are often two of us showering one right after the other. I'm going for a continuously rated one this time.

 

[WHPES]

Go for a Stuart Turner pump as they are far superior.

 

[Foxtrot Oscar]

Yeah, I'm considering the Monsoons. Only I can get a 1.5 bar continuously rated Salamander for £120 when the equivalent Stuart Turner is like £200 more, for the same water 😀.

 

[Billy Bob Bob]

Yeah, I'm considering the Monsoons. Only I can get a 1.5 bar continuously rated Salamander for £120 when the equivalent Stuart Turner is like £200 more, for the same water 😀.

you get what you pay for,after the salamander fails a few times you will wish you bought the Stuart turner monsoon the daddy of shower pumps

 

[Foxtrot Oscar]

Moving house in two years so I'm hoping with an air free install, it'll last the distance. Decisions decisions! The budget's there, I just don't want to be shelling out for the next guy's pump 😛.