Shower 'pulses' when used

[Cyclone]

My ensuite shower has started pulsing when it's used. It's not designed to, it's not a massage shower head or anything.

 

If you adjust the temperature, the flow comes back up for about 3 seconds and then goes back down, and then resumes pulsing. It doesn't matter whether you turn the temp up or down, it always helps briefly.

 

My only theory is that maybe some debris has got caught inside the valve, is that possible?

We first noticed the problem after having work done in the main bathroom, but not for several months as we were mainly using the new shower and didn't use the ensuite one!

[*Wallace*]

I would think debris of some kind or an air lock ?

[Cyclone]

Does it need a plumber to fix it? Or can a show valve be dismantled from the outside?

 

Small airlock would possibly explain it, hadn't thought of that.

[Mr Bloke]

My ensuite shower has started pulsing when it's used. It's not designed to, it's not a massage shower head or anything.

 

If you adjust the temperature, the flow comes back up for about 3 seconds and then goes back down, and then resumes pulsing. It doesn't matter whether you turn the temp up or down, it always helps briefly.

 

My only theory is that maybe some debris has got caught inside the valve, is that possible?

We first noticed the problem after having work done in the main bathroom, but not for several months as we were mainly using the new shower and didn't use the ensuite one!

Have you tried Googling?

[geared]

Is it an electric one??

 

Our old electric one started playing up abit before it died.

It had a small filter bit inside that was mucky and clogged, didn't see the sodding thing till it was broken and off the wall.

[Cyclone]

It's not electric, gravity fed mixer, with 2 controls, 1 temp, 1 flow.

 

Of course I've tried googling! None of the explanations (pressure imbalance seems to be the most common one) make sense, given that the problem only appeared after the main bathroom was refurbished...

 

I've just been playing with it, it seems that the cold water pressure is very low (obviously I don't often run it on super cold), but it's mains fed, and is visibly much lower flow rate than the tap in the sink next to it, so perhaps a partial blockage on the cold? And the pulsing IS down to a pressure imbalance because of that.

Edited November 29, 2016 by Cyclone

[Alcoblog]

I'd be investigating the airlock theory for starters.

[Cyclone]

I'd be investigating the airlock theory for starters.

 

Is there some way I can investigate?

[Alcoblog]

Is there some way I can investigate?

 

I don't pretend to be an expert, but can you turn up the water pressure (or down) and see if the air block could be removed by turning the shower on? (is there a valve?)

Also, is there a thermostatic valve in the shower?

[Cyclone]

Yes, thermostatic valve, and if I adjust that the pressure comes up for a few seconds and then drops again.

Not sure how I could vary the input pressure, apart from turning down the cold water feed at the mains, but given that the cold pressure seems to be very low would this help?

 

Definitely can't be turned up.