Boiler lost pressure again - help!

manchestermiss_2

I need some advice on what to do next.  I've got a main elite combi boiler, 7 years old and serviced every year since installation.  I noticed it was losing pressure at the end of Feb this year and called in the plumbing and heating firm we've always used.  The conclusion they eventually reached after 3 visits was it wasn't a leak in the central heating system it was the heat exchanger that needed replacing and advised we go through baxi as that was the most cost effective way to do it.  At that point the boiler was going from 1 bar to 0 in 24 to 36 hours.  

Baxi came 2 weeks ago and also agreed it was the heater exchanger.  No issues for 2 weeks after a new heat exchanger and tonight I've got an E119 error again and the boiler is totally empty.  I'll ring Baxi again in the morning as a starting point but I've got no idea what to do next.    

I've no visible leaks anywhere and all the rads have been bled and checked for leaks.  

ThisIsWeird

Have you topped it up again to get it working? If not, do so, to 1 bar, and then closely monitor what the pressure does as you turn on the CH. Keep monitoring for a good hour, especially watching what happens over the first half hour.
Starting at the 1bar, what happens?

manchestermiss_2

Yes I repressurised up to 1bar last night.  It had lost no pressure overnight, I checked before leaving for work.  I'll have monitor what the pressure gauge does when I home from work and switch the heating on.  

manchestermiss_2

ThisIsWeird said:

Have you topped it up again to get it working? If not, do so, to 1 bar, and then closely monitor what the pressure does as you turn on the CH. Keep monitoring for a good hour, especially watching what happens over the first half hour.
Starting at the 1bar, what happens?

Okay so. Pressure bang on 1 bar when I got in from work.  Drops to 0.5 when the CH comes on and rises back to 1 over the next 2 hours.  CH goes off pressure goes up to approx 1.3 bar.  

ThisIsWeird

That's interesting. It means that I haven't a clue what's going on :-(
See what happens overnight.

manchestermiss_2

Held pressure overnight.  I feel like I'm about to go down the trace and access route now with the insurance company.  The baxi engineer said he's out of ideas this morning.  

ThisIsWeird

Pressure held when turned off overnight? So when does it now lose pressure - when it's on during the morn or eve?

Lorian

Is the prv pipe on the outside of the house dripping or damp

manchestermiss_2

Lorian said:

Is the prv pipe on the outside of the house dripping or damp

Bone dry.  It's had a bag over it on several occasions.

This morning I've found a dripping radiator so I think I've cracked it.