Water output to all taps is really slow to the point that it is impossible to shower - cold water supply is fine from taps serviced by this boiler. What might be the problem?

Combi-boiler-turn hot water tap on/off and the heating stops for ...

singletrackworld.com/.../combi-boiler-turn-hot-water-tap-onoff-and-the-...

Combi-boiler-turn hot water tap on/off and the heating stops for 20secs ... hot watertakes priority over central heating so when you run the hot tap, heating is ... Yeah onmy worcester combi there is a diverter valve - it feeds either the heating or ...

My central heating works but I have no hot water - 24'7 ...

https://www.247homerescue.co.uk/my-central-heating-works-but-i-have-...

Diverter valves switch heat between the hot water and the central heating. When youturn your hot tap on, the diverter valve temporarily shuts off the water supply ...

Does your boiler keep switching itself off? Here's why ...

www.dhs-uk.com/does-your-boiler-keep-switching-itself-off-heres-why/

Jul 7, 2015 - ... Bathroom Suites, - Showers, - Wet Rooms, - Taps and Accessories, Information and ... Low water pressure can cause your boiler to turn itself off. ... boiler is not turning off, you aren't getting the amount of hot water you require. ... If there is air in your central heating system, then your boiler may shut down.

Boilers are inherently dangerous for the average DIY for so many reasons, contact British Gas and have them come back and fix it, tell them it was fine before the "service". They may simply have a control valve shut off.

If no hot water it is the diverter valve in the boiler. If no cold water the tap in the mains water supply to the boiler may be turned off

It is the shower head or plumbing that has a built in mixer or reducer.

The problem is not the water heater. The shower has a mixer or a limiter built into the plumbing so that the water wont get hot. It is a safety feature to prevent burns and protect children from scalding.

Hi, if you have a mains pressure HWC, all you need to do is shut the cold mains off either from your cylinder cupboard or on the street. Shutting it off on the street is probably better as things like shower valves tend to pass water through and start a back feed.

Oh some of these there was a small black heatexchanger just for hot water they some times block up . or it could be a blockage in the water section where it flows in .I know Valliant have a very good tech line and fitters who do house calls .

if cold supply to boiler and shower are off the same feed this could be your problem as the boiler governs flow of hot water best of luck

water must be set at 3lts a min ,check diaphragm valve move when hot tap is on, check microswitch ,best of luck

mixing valve must be replaced