Shower pump regularly air locked

Dick Turnip

I had the bathroom redone a year ago, new shower and pump. Shower was working fine for the year. Fast forward to just before xmas and the shower stopped working, called out an emergency plumber as it was xmas week and he said I should get the pump replaced as it was still in warranty, but also that he wouldn't personally have installed it as he said it was cheap (Stuart Turner showermate).

So I decided to bite the bullet and get a brass plated one (Stuart Turner Monsoon). Got a different plumber out and he installed the new pump and shower was working.

A week later and it stopped, the plumber who installed the new pump called out again, said it was an air lock and cleared it, showed me how to clear the air lock if it happens again. He checked the tank in the attic to make sure the tank wasn't emptying quicker than it could refill, all ok there.

So, a few days later it goes again. This time I followed his instructions and it worked again.

A few days later, goes again. I repeat, leave the hot on full blast for 5 mins, then the cold for 5 mins. Worked again for 3 showers over last 2 days, and now it's gone again. Losing my fcuking mind with it now.

Anyone here advise why this might be happening? The pump is in a hot press on ground floor beside hot water tank, shower is on first floor, water tank in the attic. The pump is 2bar positive pump. There had been logs & briquettes stored on the floor near the pump, so maybe some of the dust or dirt from the briquettes got in to the pump?

Could grit get in the pump and cause it? Is it a case of turning off power and cleaning out filters and trying again?

Any advice appreciated!

Sleeper12

I agree that the showermate is cack.

The tank could indeed be filling too slowly at certain times of the day.

Another possibility is that it is plumbed incorrectly on the hot side and it could be sucking in air from the hot water cylinder.

Did a Stuart Turner engineer come out to repair the Showermate? He would have picked up on an incorrectly plumbed pump very quickly. It would have voided the warranty

John.G

Is the pump air locking on both hot and cold legs?. you might post a few photos.

Dick Turnip

https://www.boards.ie/discussion/comment/120132023#Comment_120132023

No, so I informed the original plumber/builder that did the initial bathroom refurb and installed the pump when the showermate vent, and he said that I'd need to contact the supplier he bought it from as they would send out stuart turner engineer and pump to install, he wasn't allowed do it. Not sure how true that was, but it was the week leading up to christmas, I have friends staying in the house so I needed to get it sorted quickly.

I contacted the supplier, they said it was in warranty and would send out a new one. That never arrived before xmas, rang them after and they said it stuart turner messed up that week's shipment and they didn't have a replacement in stock.

So after getting the advice from the emergency plumber that said the showermate was crap, I ordered a monsoon from another supplier as it was in stock (I guess I'll sell the showermate on done deal for a discount to try get some cash back on it).

The lad that installed the Monsoon, wasn't a Stuart Turner engineer, he was from another of these emergency callout services.

He did check the attic tank after clearing the air lock, but perhaps he got it at a good time of day. Would a 2 bar be powerful enough to empty the tank?

Re the plumbing on the hot water tank, it was working fine for 5 or 6 months after install, so I'm not sure it would be that either?

Sleeper12

I have seen electric showers putting out around 4 litres per minute, use water faster than the tank was filling. Your 2 bar pump will be putting out at least 10 litres of water per minute & probably close to 15 bar per minute. You would need to check the level of water in the attic tank immediately as the pump becomes airlocked.

If it's plumbed incorrectly on the hot side then it can suck in air from the expansion pipe

John.G

Run the shower into a bucket for exactly 30 secs. then measure this with a 1 litre milk bottle or whatever and X 2, this is the shower flowrate in LPM. Look at the label on the CWST which should give its volume in Litres, divide this volume by the shower flowrate to give the minimum shower run time even without any makeup, a 150L CWST with a shower demand of 15LPM will last 10min but assuming at a 5LPM make up then the shower will run for 15min. a 200L CWST under the same conditions will give 10 & 20min run times. if problems appear within those time frames of say 15 to 20minutes then CWST suspect, otherwise not IMO.

monseiur

Has the air lock occurrence any noticeable pattern - does it happen in the morning when perhaps more than one toilet is being flushed at the same time, multiple sinks/basins etc. are being used hence drawing more water than the attic tank can supply. If so you may have to fit a bigger storage tank in the attic or fit an extra one or two if you can fit them beside the existing one and plumb in line using 25mm or bigger pipe.

Dick Turnip

Thanks for the replies folks - will go through and reply to later, was away for the weekend, but cleared the air lock last night when I got back.

There was no hot or cold water coming out of the shower yesterday. So, I unscrewed the 'cold in' pipe , and ran it into a bucket, then reattached it, and disconnected the 'cold out' pipe and ran it into a bucket, so that cold water was running through the pump. I reattached it and tried the shower again, and it was flowing again - both hot and cold water.

Dick Turnip

https://www.boards.ie/discussion/comment/120145613#Comment_120145613

No, there's only one bathroom in the house, so it's not that there would be multiple sinks/showers/basins pulling from the tank at once.

The plumber that installed the pump did go up in to the attic to look at the tank when it was running to make sure the tank wasn't emptying quicker than it was able to refill. Perhaps he didn't watch it long enough, I better do that myself again.

Dick Turnip

So I ran the shower for 15 minutes in total this morning - 5 mins cold only, 5 at hot only, 5 at mixed. I was in the attic looking at it the whole time and the water level remained the same throughout.

The water tank is a W50 tank, which seems to be a bit of a misnomer as it is actually 43 gallons. So I think that rules out the CWST emptying out as an issue? One thing to note though - there's a some sediment settled on the bottom of the CWST, is that normal? Could that be causing an issue?

Attached is a picture of the hot water tank and shower pump setup. So the hot water tank was replaced last year. Looks to be a mixture of the original piping and new piping there.

IMG_20230124_111240.jpg

John.G

You are, more than likely pulling air in from the vent , check out these suggestions.

Stuart Turner Monsoon-Universal.pdf

spaceHopper

It's connected to the top of the hw tank. I'm not plumber but that looks wrong to me, it's pulling HW from the top of the tank then if the tank is vented it could pull in air. Is there a one way valve on the vent/overflow pipe?

Wearb

If its pulling air in through the vent then a Surrey Flange would most likely sort it out.

monseiur

Think you have hit the nail on the head there Wearb well done

Dick Turnip

Thanks for the advice all. I ended up booking an appointment with the ST agent, so waiting for that to happen - waiting list of a few weeks.