Should the Vap not take its feed just before the HBV and then back in after the Heater Matrix. ie, in parallel with the HBV / Matrix
I cut the top pipe which goes from the thermostat - HBV and put the vaporiser inline so you get a constant flow.
I will proof read what I type one day
If you suspect the Vap or a Tempreture issue, cheapest way to start is to give a good Flush and Reverse Flush the Vap as few times, whats the Coolant like and when was it changed last.
I had a Corsa Temp / Vap issue recently that was throwing all sorts of wonderfull problems at me, about 4 flushes later with Dish washer tablets and a drop of Fernox in the Cooling Sysytem soon sorted out over a few weeks, best do iut now before the Cold Weather licks in
Mmmmm
I have been setting the heater to 20 deg at start up over the past few days but couldn't make up my mind if it was any better of not
Last coolant change must be getting on for 3 years ago when the piggin oil cooler went
Even though the heater matrix gets hot pretty quick, it can't do any harm to pull the pipes off the vaporiser and give it a flush.
Come to think of it, I did have a problem earlier on in the year with the gas pressure fluctuating but thought it may be the vaporiser which after all is 6 years old now.
Me thinks you might be onto something there
I'll have a play over the next few days .................
Cheers lads