Saunier Duval HW problem

[rmtebbot]

Hello gents

I'm currently having my kitchen/bathroom redone, and they're almost finished, however we're having problems with the boiler (a Saunier Duval Thelia 23E)

The CH comes on ok, but it makes a whoosing sound as if the boiler is filling up with water or the pressure is increasing and decreasing, and then as soon as we turn on a HW tap the pilot goes out.

From what I've read on these forums I'm wondering if it's a problem with the diverter valve diaphragm? Any ideas?

The other problem is that the pressure guage seems to be stuck on just over 1 bar, which obviously isn't helping matters.

If anyone could help I'd be most grateful, We've been without HW for about 3 weeks!

 

[Agile]

Have you tried increasing the system pressure?

It sounds as if its empty!

Tony

 

[rmtebbot]

Would the CH work if the system was empty?

As the pressure guage is stuck it's difficult to tell.

The boiler was not lighting at all a few days ago and the plumber we're using told me he would bleed the system. I assume he must've refilled it to make the CH work, but every time HW is demanded the pilot goes out.

 

[Agile]

Never assume anything!

Why do you seem to be so resistant to increasing the pressure???

Tony

 

[rmtebbot]

Sorry, I'm not resistant, I'm just at work at the moment!
I'll have a look tonight, cheers Tony

Do you know of any reason the pressure guage might be sticking? I think that'd help me in my investigation!

 

[gas4you]

Quite often a very small bit of crud in the system water can block the pressure gauge inlet tube on a lot of boilers, not just yours. Ideal minis seem the worst for this that I have come across.