Worcester 28i RSF Constantly at 3.5 bar help!!!

[TAH]

Hi
This is my first question on here, please help if you can.
My boiler is 5 years old and I've had no problems.Just lately i noticed the pressure was at 3.5 bar so I drained the system to reset the pressure to 1.5 bar -as recommended. After using the cental heating and water over night, I checked it again and the pressure is back up to 3.5 and thats with no use of hot water or central heating.

Please can anyone suggest anything.It will be greatly appreciated.
Many Thanks
TAH

 

[Dan Robinson]

Either your filling loop is letting by - or you have a failed/depressurised expansion vessel.

 

[clf-gas]

One of several things TAH. start with.

1: The filling loop is letting by thus increasing the pressure.
2: The heat exchange has a hole letting from mains to heating.
3: Pressure guage faulty.

1a: Drain pressure back down to one bar, disconnect the filling loop from heating side, check if this constantly runs, if so replace. if not the loop then watch for increase in pressure on guage (this may take a few hours) if it does increase turn off mains water issolation under boiler and observe for stabilisation (again for a few hours).

Thats 1 & 2 covered, if niether produce result then 3: faulty guage, rare but I do get this.

 

[TAH]

Thanks very much for your help-I'll get on to it and get back to you.
Cheers for your speedy reply.
TAH

 

[TAH]

Hi I tried all the above and it looks like the a cross leak to the heat exchanger.
Are the parts easy to get?
Is the installation straight forward?
Worcester quoted me £185 call out and £245 for heat exchanger!!!

I'd appreciate any recommendations or further advice.
Thanks
TAH

 

[nickso]

doesnt the 28i have a twin pass heatex?

not likely to be cross leaking if it does.

 

[TAH]

One of several things TAH. start with.

1: The filling loop is letting by thus increasing the pressure.
2: The heat exchange has a hole letting from mains to heating.
3: Pressure guage faulty.

1a: Drain pressure back down to one bar, disconnect the filling loop from heating side, check if this constantly runs, if so replace. if not the loop then watch for increase in pressure on guage (this may take a few hours) if it does increase turn off mains water issolation under boiler and observe for stabilisation (again for a few hours).

Thats 1 & 2 covered, if niether produce result then 3: faulty guage, rare but I do get this.

The 'cross leak' reference was made by the technical support team at Worcester Bosch.
It was also mentioned on point 2. by clf-gas above

 

[TAH]

Hi I'm not a plumber(as you can tell) and I'm not aware of the differences between a twin heat ex and the other.

I appreciate any input on this, even if it is to dismiss the claim that it is a heat exchanger leak.

 

[Terrywookfit]

doesnt the 28i have a twin pass heatex?

not likely to be cross leaking if it does.[/quote

Why not ??It is W B!!

 

[clf-gas]

doesnt the 28i have a twin pass heatex?

not likely to be cross leaking if it does.

Plate to plate HE

 

[Terrywookfit]

I thought 28I was Junior which is Bi Thermic!!

 

[Dan Robinson]

Same thing isn't?

Bi-thermal
gas to water
heat
exchanger

from de manual

 

[Terrywookfit]

Same thing isn't?

Bi-thermal
gas to water
heat
exchanger

from de manual

Are you trying to say that Bi thermic is same as plate to plate

 

[Dan Robinson]

No.

 

[Dan Robinson]

Bi-thermic as I understood it would mean two circuits of water directly heated by gas, with primary water assisting the secondary heat up (a la Puma's)

Plate-plate. Would mean a heat exchanger as found in Ecotecs, Turbomax, Isars, etc.,.