Sorry all more power shower air problems

Nick Newbold · 27 Nov 2019

First of all I have searched here and many other places.

I am have problems with air in being drawn into the pump and giving very poor flow rate.
The cold is a dedicated direct 15mm feed from the tank in the loft.

I have a tech flow 49041 pump connected through a Surrey flange and other hot water supply trough the horizontal pipework. The vertical vent to the tank in the loft. I have checked when turning the pump on using a glass of water that the vent is sucking Air(water). Any idea what I can do I am at a loss here

Am trying to upload some photos but have difficulties, will post this and continue trying.

all help appreciated

Madrab · 27 Nov 2019

Ok so if the vent/primary hot supply and the pumped hot supply are separated by the flange then the only other thing that can be going on here is that the pump is drawing hot water out of the cylinder faster than the cold supply from the cistern can replace it and the pump is causing a pulling on the other outlet and thereby the vent, therefore sir bubbles will be getting drawn down into cylinder and then into the pump.

Is this a new problem? Is the feed to the cylinder (gate valve?) full open? Is there anything in the bottom of the cold water cistern that blocking the feed?

Looks like it may be something to do with the supply circuit from the cold cistern to the pump.

Nick Newbold · 27 Nov 2019

The main cold feed to the WT is fully open. Cistern is clear

Had this problem since the pump was fitted some 3 years ago, getting worse now, think the pump maybe dying due possible damage.

IMG_4157

Nick Newbold
27 Nov 2019
1

sorted posting pics

You can see the setup now, the T connector from the Surrey Flange goes to the Pump(right) and the rest of the house HW supply. and top outlet vent to the CH tank.

The cold is directly from the water tank in loft (15mm)

IMG_4158

Nick Newbold
27 Nov 2019

in this picture the hot supply breaks into two going to the main bathroom shower/tap and into the en suite shower directly behind wall

Nick Newbold · 27 Nov 2019

Forgot to say thanks for the help

Madrab · 27 Nov 2019

Oooo, someone likes speedfit ...

Normally the rest of the house HW supply would be fed from the same pipe as the vent. Normally it would tee - down for the supply - up for the vent. That way the pump has a dedicated supply from the surrey. I would look at that first. The other thing is if the pump has been cavitating for three years then your lucky it's lasted this amount of time before getting worse.

Is the tee'd supply pipe to the pump rising too??

What size is your cold water cistern (CWSC) in the attic?

Nick Newbold · 28 Nov 2019

I didn’t do any work on the system.

yes, more I look at this I think that I have to cap the top pipework from the flange and then connect the lower pipework which is feeding the hot water supply to the vent. hate using the push fit though, might try this and assuming it works get a Plummer in to sort it.

Madrab · 29 Nov 2019

You always want to keep the supply coming out of the top of the cylinder as the vent but then it'll tee down to feed the rest of the house as well. The side outlet from the surrey then becomes the dedicated supply to the pump.

dilalio · 29 Nov 2019

As @Madrab posts... That's been plumbed wrong. The whole point of a Surrey is that it should provide a dedicated feed to a pump. You'd get all sorts of issues with the set up as it is now. Surprised your pump has not been constantly hunting as well.

Look at the installation instructions of any pump and it will show you preferred setup.

Madrab · 29 Nov 2019

Yep I have to say that it has all the hallmarks of a DIY job by someone that didn't really know what they were doing. All the speedfit, PTFE tape on the compression fitting threads, the flexi through the wall, the side outlet of the surrey feeding the pump and the rest of the house. It all really needs reset and redone by an experienced plumber.

The top outlet from the cylinder (flange) should never be capped, it is correct at the moment in so far as that pipe should always be the vent but that pipe would also feed the HW to the rest of the house.

Nick Newbold · 29 Nov 2019

Thank you all for your help really appreciated, I am organising for a Plummer to come round.

dilalio · 30 Nov 2019

Nick Newbold said:
and top outlet vent to the CH tank.

I hope not!

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sorry all more power shower air problems

Similar threads