What the hell is wrong with my shower?

[TheBullfinch]

I had a shower (over bath) installed just before lockdown last year. The bathroom didnt have a shower prior to this.

I booked a plumber who was local and had good feedback and he installed a Triton shower (not electric),

Throughout the summer, it was great but as the weather cooled, it started to fluctuate in temperature. I thought I'd have a fiddle around with the knobs and central heating settings to rectify things (boiler is only 5 years old).

It hadnt improved by January so i called the plumber who said he'd come and look at it. He didnt. Despite me chasing him several times, he now appears to have retired and moved.

Does anyone know what's wrong?

When I switch it on, it goes from hot to cold to hot to cold before finally settling on hot after about a minute and a half (while I'm standing there, freezing).

I've tried calling a few plumbers but they all seem to busy until June!

There's only me in the house so its not a case of other people flushing/turning on the tap.

Ours has gone like this, the previous one (similar model) was fine so I guess it's a fault with the actual shower. Also Triton I think.

Oh balls. Really? OK, I'll have a look at the Triton website.

I'm so glad summer's coming.

I think what you describe is usually a valve thing?

yes it sounds like a sticky or faulty valve but could also be the pump you need Piglet John

Try taking out the cartridges and soaking them overnight in vinegar. It might just be a limescale problem. I had this every 18 months when I lived in London.

Is it a gas boiler? Combi?

It may be a valance problem but when we had this is was a pressure issue. The fitter had used a positive pump and it should have been a negative ( or vice versa.. it was a while ago!).
If you don't have mains pressure I'd guess it's the pump.
Is PigletJohn still around?

Valve not valance

Its a Worcester Bosche Gas boiler.

Cartridges? I'm going to have to Google that.

Interesting comment about Limescale. I have a weekly battle with the stuff. I get through gallons of Calgon.

There's lots of mains pressure. So much so, that he turned all the inlet valves to the taps down while he was here because they were gushing like Niagara!

Righto - so Ive learned how to isolate the supply and now I'm going to descale the cartridges to see if that works.

Descale the shower head too. That used to be enough to set my shower going hot and cold, when it got a little blocked.