Power Shower - Air Locks

[DonnyO]

Can someone help me here please.

I get major problems with air in my power shower system interrupting the hot water supply. The pump also 'surges' i.e. switches on & off without the shower being run. The problem is worse when the shower hasn't been used for a few days, the air seems to build up.

The problem is relieved by turning off the power, removing the shower head & running the system until the air is purged.

Heres the spec.

Watermill SS70DLV shower pump
Standard open vented indirect sytem with standard copper hot water cylinder
The pump is fed by 15mm pipe via a surrey flange from the cylinder and is situated on the floor next to the cylinder.
The shower head is in another room, same level but approx 5metres away. This is fed by 22mm pipe from the pump to the shower mixer.

Any ideas gratefully received.

 

[tekkiesteve]

Any non return valves fitted, if so have you checked them?
Steve

 

[DonnyO]

No none fitted.

 

[grrinc]

Is the cold supply fed directly from the CWT? It will need to be.

If it is supplied from the CWT, another problem is if it is tapped in too close too the float valve. These ususally 'gush' in a lot of air when they are filling up and this air can be sucked down your supply to the pump.

I have also seen (bad) plumbers remove the the air baffle on the Surrey Flange prior to fitting it. One chap once said that he thought it was just a packaging thing!! This is very rare though and shouldnt make too much of a difference if it was missing.

 

[DonnyO]

Thanks for reply but yes it does have own cold supply & the feed is at opposite end of tank to ball valve. Guess the baffle could be missing. Haven't checked.

 

[Bryan King]

you have a 15mm supply to the pump and a 22mm supply from the pump to the shower?

A Shower pump is designed to push water rather than pull it, so the feeds to the pump must be adequate to supply the outlet pressure.ie you may be trying to pump water at a greater rate than the supply will allow.

 

[DonnyO]

Thanks Bryan, thats sounds logical. I'll convert the feeds to 22mm.

Fingers crossed.

 

[DonnyO]

Thanks Bryan, thats sounds logical. I'll convert the feeds to 22mm.

Bryan, thanks a lot, converting the feeds to 22mm has solved the problem.

Much appreciated.