Replacing a failed hot water pump.

[mj2000uk]

Hi all,

Hoping for some wisdom here!!!

We had a hot water pump fitted just last summer. The pump has failed and the original installer is now hiding from us and giving no support.

The good news is that the pump can be replaced by me as a like for like but I am unsure about shutting off the water to it.

The pump is installed in line with the hot water outlet pipe from the cylinder which is in the storage cupboard on our landing. The cylinder is fed cold water from the tank in the loft and the cold water pipe has a shut off valve to the cylinder.

Is the process as follows -

• Turn off cold water at valve.
• Run hot water taps until no more water comes out.
• At this point, replace water pump.
• Once replaced, close all hot taps and turn cold water supply back on to fill the cylinder.
• Once full, run hot water taps without pump for a few minutes to remove any trapped air.
• Turn on pump and test.

I am just worried that any of the trapped air in the cylinder will go somewhere else or do something malicious to my plumbing elsewhere!!!

Thanks in advance for any help.

By the way, the pump in question which has failed after 12 months is a Stuart Turner Techflo Single Impeller pump. I hope the replacement will last more than a year as I am convinced that the one installed fell off the back of his lorry or van or whatever!!!

 

[HERTS P&D]

Do you have a wet vac?

Andy

 

[mj2000uk]

Do you have a wet vac?

Andy

It's an airing cupboard......I have lots of towels!!!

Am I about to flood the house?

 

[terryplumb]

Post pics of pump / cylinder set up. Doing as you suggest does not empty the cylinder ,not that you necessarily need to empty it anyway.

 

[mj2000uk]

Thanks, see images below.

 

[terryplumb]

Isolate electric supply to pump ,and prove dead. Isolate cold feed to hot water cyl. Turn off whatever it is that heats the water ( immersion or other )Turn on all hot water taps. I cant see if the black hose ends going to pump have built in isolaters ( just a screw ,quarter turn ) . if they do isolate them and remove the pump. Be Aware that the pipework will still contain water that you must contain ,but if the flexis have isolators you can control that better. Fit pump and when all else is reversed ,make sure all hot taps run full flow ,before switching pump on.