Boiler repair advice

Tucker

I have a saunier duval F30E combi boiler. It's been faultless for 6 years and still works fine, but I seem to have a small issue with a valve that needs replacing.

Last autumn I drained the whole system and flushed it out, refilled and added fresh inhibitor.

I've bled the rads a few times since to get all of the air out of the system. Each time I've topped it up .1 of a bar or so to pressurise it to the correct level.

After each top up via the built in fill loop, the boiler over the next 24 hours has spat water out of the reduced pressure zone valve which is part of the fill loop.

This is not the discharge safety valve that pushes water to the outside drain when the boiler hits 2.5bar, it's a valve that is part of the fill loop.

I am not sure what it is exactly. Some sort of backflow valve to prevent water from the system going back into the supply?? Does anyone know of it's function.

Basically, it looks easy enough to remove and replace.

Can anyone confirm why it's spitting out water after a top up?

Is it a case of replace the part or do they have o rings that can be replace in them?

Can anyone offer some information?

ormus

its a non return valve. sounds like it needs a new one.
they dont last forever.

Tucker

Thanks. Suspect you are right.

It looks simple enough with the right replacement part.

keystone

Tucker wrote: »

After each top up via the built in fill loop, the boiler over the next 24 hours has spat water out of the reduced pressure zone valve which is part of the fill loop.

I think, as Ormus suggests, you mean the Non Return Valve?

Some sort of backflow valve to prevent water from the system going back into the supply?? Does anyone know of it's function.

Thats exactly what its for.

Basically, it looks easy enough to remove and replace.

They are but I'm not that convinced you need to.

Can anyone confirm why it's spitting out water after a top up?

Where does it spit water out of? The Hexagonal Nut in the Centre? If that has been undone it will. Said nut is the visible part to that which holds the internal guts of the valve in place.

Cheers

roger196

The filling loop is meant to be removed, in accordance with the water by-laws, after it has been used to top up the boiler pressure . There should be a tap at the boiler end which must be turned off before removal.
If the by-laws have been changed, no doubt someone will update.

Tucker

In the service manual it's referred to as a Reduced Pressure Zone Valve. Best way to demonstrate is if you look here at the PDF version of the manual:

http://www.ultimatehandyman.org/PDF/Saunier-Duval/Saunier-Duval-Thema-Classic-F30E-Insallation-manual-47-920-36.pdf

Page 29, diagram number 4, it shows you the filling loop and the valve in question, marked with a white arrow which it discharging after a top up. It says on commissioning the boiler and the initial fill, it's not uncommon for the valve to release a small discharge. But it's only recently done this when topping up after I have bled the system and the amount last time was more than a small discharge.

I noticed yesterday when I first opened the fill loop, I could not hear any water entering the system. It seemed the RPZ valve was preventing it entering. I opened and closed it a few times and then the water fed in. It just seems like it's sticking and not operating correctly.

ormus

roger196 wrote: »

The filling loop is meant to be removed, in accordance with the water by-laws, after it has been used to top up the boiler pressure . There should be a tap at the boiler end which must be turned off before removal.
If the by-laws have been changed, no doubt someone will update.

those laws only apply in certain areas.
not all water boards are the same.

Tucker

Both this boiler and the last boiler I had, had an integrated filling loop, so I am not aware it's a problem.

I top up the boiler again after it discharged some out of the valve yesterday and this time it's not spat any out, so it might just be one to keep an eye on as it's not letting anything out during normal operation.