Turning off water supply to combi boiler

[pistolpedro]

Boiler: Worcester Greenstar Junior

Need to replace the washer on the hot water bath tap

The tap is a mixer but it has separate knobs for hot and cold,

Planning to turn the water off outside and turn off the electricity to the boiler

There is a large water tank (guessing this is cold water) in the loft does this need to be drained?

My main concern is turning off the water to the boiler, once the hot pipes are drained and i have replaced the washer is it just a case of turning the water and power back on, or does the combi boiler need to be bled or re pressurised?

 

[seco services]

just shut the cold mains stopcock.
then turn back on when washer fitted.

whats the tank in loft supplying ?

 

[pistolpedro]

thats great thanks

Im not sure to be honest, the bungalow was built in 1968 could it be part of the original system that has not been removed? its right on the other side of the loft and very hard to access so i cant give it a knock to see if there is any water in it

 

[digdilem]

The pressure guage on a combi relates to the central heating loop (although there's a pressure switch on the hot water circuit too so it knows when to fire).

Turn off the electric then the stop cock, run the taps until the water stops, you'll be reet.

If you didn't turn the leccy off first the combi would try to fire, overheat and lock itself out. Would probably need a reset after, but should fail safe.

When done, just turn the water back on, check for leaks where you've been working and if ok, turn the combi back on. Boil a kettle and have a cup of tea, you won't need to turn the filling loop back on as you haven't disturbed the heating circuit.

 

[nogoodatfaultfinding]

The pressure guage on a combi relates to the central heating loop (although there's a pressure switch on the hot water circuit too so it knows when to fire).

Turn off the electric then the stop cock, run the taps until the water stops, you'll be reet.

If you didn't turn the leccy off first the combi would try to fire, overheat and lock itself out. Would probably need a reset after, but should fail safe.

When done, just turn the water back on, check for leaks where you've been working and if ok, turn the combi back on. Boil a kettle and have a cup of tea, you won't need to turn the filling loop back on as you haven't disturbed the heating circuit.

turn off the cold supply under the boiler. Why bother with the stop tap?

 

[digdilem]

Because OP knows where the main stop cock is without telling him to look for something else...

 

[pistolpedro]

All done thanks for all the advice

washer looked in fine order few small specs of dirt which i blew out, took the brass gubbins to bits and reassembled seems to be working fine now