Worcester 28i RSF pressure problems

[tpagr8]

Hi,

My Worcester 28i RSF keeps losing pressure. The pressure relief valve was replaced before Christmas as it was constantly leaking and pressure dropped to 0 on the pressure gauge. This was replaced and everything was ok for a few months. Now the pressure is dropping again. I refilled to 1 bar and immediately the pressure shot up to 3 bar and water was ejected via the pressure relief outlet but the pressure did not reduce on the pressure gauge. I thought the pressure gauge must be faulty as I had only put a little water in so I put a very little amount of extra water in and the pressure started to drop immediately. Any thoughts on what the problem could be most appreciated. Could it be the pressure gauge that is faulty?

 

[grahamgas]

Did the pressure rise whilst the boiler was running or did rise to 3 bar cold.

If it did it with boiler running, then your expansion vessel is probably shot.

If it did it cold, then the heat exchanger could be holed, thus allowing mains water to enter the system, thus increasing your pressure.

Hope this helps

Graham

 

[tpagr8]

Thanks for the reply. It was when the system was cold, I guess the heat exchanger will be an expensive job.

 

[moogwai]

i think it's a gas to water heat exchanger on this model without a divertor valve so i wouldn't of thought it to be the heat exhanger. the 28cdi rsf does have the plate heat exchanger on.

isolate flow and return on boiler and see if pressure still drops/rises, if you do this you know the prob is somewhere inside the boiler...if pressure stays the same it indicates you may have a leak on pipework.

 

[tpagr8]

Thanks moogwai, I'll give it a go. Need to look at the fridge/freezer first..it has just packed up aswell!

Yes it's a gas to water heat exchanger- part no 87161429050

 

[moogwai]

Need to look at the fridge/freezer first..it has just packed up aswell!

whoops.

 

[tpagr8]

Just dropped the front panel and took the inner casing cover off. Water is seeping from the top of the Auto air vent, running down the pipe, out of the unit and onto the floor. Presumably that has something to do with the problem?

 

[moogwai]

could be....replace it.

 

[grahamgas]

Doh

Should read the post clearly first!

 

[RoryD]

Hi,

My Worcester 28i RSF keeps losing pressure. The pressure relief valve was replaced before Christmas as it was constantly leaking and pressure dropped to 0 on the pressure gauge. This was replaced and everything was ok for a few months. Now the pressure is dropping again. I refilled to 1 bar and immediately the pressure shot up to 3 bar and water was ejected via the pressure relief outlet but the pressure did not reduce on the pressure gauge. I thought the pressure gauge must be faulty as I had only put a little water in so I put a very little amount of extra water in and the pressure started to drop immediately. Any thoughts on what the problem could be most appreciated. Could it be the pressure gauge that is faulty?

The expansion vessel absorbs the expansion in the system when hot (funnily enough!!). It has to have approx .75bar of air to do this. If over time the air has discharged then the system water which is hot, will get squashed in the vessel further causing expansion (the large pressure rise) and it will then discharge thru the PRV, vents etc.....A good old fashioned foot pump will provide the pressure required (whilst simultaneously holding the pressure relief valve open). This is quite common. Oh! before doing this, press on the expansion vessel schrader valve to see if water flows out, if so a new vessel is needed.

 

[Mbear]

The expansion vessel absorbs the expansion in the system when hot (funnily enough!!). It has to have approx .75bar of air to do this. If over time the air has discharged then the system water which is hot, will get squashed in the vessel further causing expansion (the large pressure rise) and it will then discharge thru the PRV, vents etc.....A good old fashioned foot pump will provide the pressure required (whilst simultaneously holding the pressure relief valve open). This is quite common. Oh! before doing this, press on the expansion vessel schrader valve to see if water flows out, if so a new vessel is needed.

It's not a Boeing 757 tyre ur blowing up

 

[tpagr8]

I've now changed the auto air vent and repressurised the expansion vessel - no water came out of the schrader valve. System is maintaining pressure and no leaks now.

Thanks to all for helpful advice

 

[moogwai]

It's not a Boeing 757 tyre ur blowing up

lol...he means 0.75bar mbear...put yer glasses and you will the "."

glad you've got it sorted now mate.