WORCESTER 28I

[LEAGUECUP]

WORCESTER 28I
PROBLEM HAPPENS WHEN DHW TAP SWITCHED OF. PRESSURE GUAGE JUMPS FROM 1 TO 2 AND BOILER THUMPS. THEN RESETS ITSELF AND RUNS FINE???????????? SOMETIMES GOES TO LOCKOUT AND HAS TO BE RESET??

 

[Agile]

It sounds as if there may be a leak from the secondary to the primary.

Its fairly easy to test for if you know how to, or if the FAQ on the site explains it.

Tony

 

[namsag]

Check that when the tap is turned off the boiler extinguishes straight away ,It sounds like yours is staying on for a bit longer and because the heat has nowhere to go the pressure then builds up and can cause lock out .
Causes can by dead leg in hot water pipework work or a sticking flow switch

 

[bengasman]

what do you mean by:

and resets itself?

AND TURN YOUR CAPS LOCK OFF

 

[LEAGUECUP]

CAPS LOCK NOW OFF

burst expansion vessell and heat exchanger passing
thanks

 

[namsag]

Very much doubt it

 

[LEAGUECUP]

filling loop disconnected boiler drained then rises to 1 bar on its own,

 

[namsag]

sounds like heat exchanger , but 28i had a bi flow heat exchanger that had seperate circuits for heat and hot water .

 

[bengasman]

burst expansion vessell and heat exchanger passing
thanks

can you elaborate on that?
Especially on the heat exchanger passing.
it does happen sporadically that a worcester has a defective plate heatexchanger that leaks water from the mains to the system.
as the i-series don't have a plate exchanger, methinks this option is somewhat unlikely to be the cause of your problem.

 

[LEAGUECUP]

WHEN I DRAIN BOILER DOWN FROM THE PRV THE PRESSURE STAYS AT 0.5 BAR, ALSO EXPANSION VESSELL WILL NOT TAKE CHARGE TRY TO PUMP IT UP BUT NOTHING REGISTERS ON GUAGE HOWEVER ON FILLING WATER WILL RELEASE FROM VALVE. REPLACED BOTH ALL OK.

 

[namsag]

Thats a faulty pressure gauge then if its staying at 0.5.
And what gauge is not registering you pumping up vessel the one on your pump or the one on boiler

 

[LEAGUECUP]

the one on my pump (pump working fine).vessell will not take a charge.
original fault is when hot water tap shut of. pressure on guage fluctuates boiler thumps for a few seconds then cheating comes on as normal

 

[bengasman]

you can check the pressure in the vessel with a simple tyre gauge,
your defective water pressure gauge probably means your system if full of carp, very common for these boilers.

 

[namsag]

i will stick with original diagnosis

 

[Agile]

The OP is being rather vague and inconsistant.

He has not made it clear if he is meant to be a plumber or a boiler owner.

Even though the heat exchanger is a four pipe they can still leak from DHW to the system.

He originally said it was giving those symptoms but later is more vague! And still has not mastered the use of the Caps lock!

Tony