Vaillant ecotech pro 28 losing pressure

[whatsthenews]

That was when it was off ,ie stat not calling for heat, neither stat nor boiler displaying the flame icon, but not sure if that would be classed as "cold" as the temp' reading on the boiler was 45c and pump may have been running. Went up to 2.1 briefly when the stat called for heat, then back to 2.0.. Thanks again.

 

[Riley]

At cold the pressure should really be between 1-1.5 bar. When you say off it hadn’t been running beforehand??
When it runs for a decent time the pressure will rise but up to say 2-2.5 bar if it’s starting higher and going to 3 bar and above then you’re going to lose pressure when the prv pops open

 

[whatsthenews]

No, heating had been on since 07.30 with stat set at 22c.Rads were warm when we got there at 11am so had been on fairly recently.
If the pressure goes too high , will a fault code show before the PRV opens? Is there fault code log that an engineer could check to see if that's what's happening?

 

[Riley]

Right so it’s not cold. That’s the starting point you need

 

[whatsthenews]

OK- how long does it need to be off for to be classed as "cold"?
I'll need to go down and turn the stat down and wait for it to cool. An hour?

 

[Riley]

It’s all relative depends how long it’s been on and what temp was achieved

 

[Riley]

I would turn the boiler off for a couple of hours

 

[Rob Foster]

My elderly parents recently moved and have had problems with the heating system since then! At first we noticed that some of the vertical rad's were barely getting warm unless the 'stat was turned up to 26c, and this is still the case.
Couple of months back we had a bloke out who took one of the vertical rad's off and drained it but it's not made any difference. The pipes either side of these rad's is piping hot, but it's not going up into the radiator even with the TRV open to max.

Over the past 2 months the pressure keeps dropping. It's difficult to see if there's a pattern to it as we don't live there, but we're having to top the system up every 2-3 weeks. No visible leaks from radiators.

Got the bloke out again and he said the expansion vessel was fine and put some sealant solution in. I've just read that this invalidates warranty, but it doesn't make any difference as apparently the previous owners didn't register the boiler and it's just to say past the 2 years.
Anyway, it's not made a blind bit of difference.

There's only been one occasion when my parents have rung us and said the heating was off, and we only top it up when it actually goes off, so I'm wondering if it's related to running the hot water more as we go down to clean once a week, and I always mop floors etc. Maybe it's just a coincidence.
I have noticed it seems to take a long time (longer than the upstairs bathroom hot tap in our house) for the water to run hot when it's been off for a while. I've tried reducing the flow from the tap, but doesn't make any difference.That seems a little strange when it's only a 2 bed bungalow and the boiler is less than 8 ft from the kitchen tap!
The bloke did mention that if the pressure is going up above 3 then water will leave the system and the boiler will cut out as the pressure drops.This boiler is in a cupboard that doesn't have an outside wall. I've seen folks tell people to have a look at the outside pipe to check for water, but where would this be? If it's a condensing boiler will it still have one?
Thinking we'll get in touch with the bloke who installed it and get him to come out.
TIA for any advice

You might look at MFD from Flowflex it will solve the pressure loss issue instantly
Rob Foster aka centralheatking

 

[Riley]

Clever tool but surely this is just masking a problem?? Plus it’s pumping fresh water in constantly which will speed system corrosion

 

[whatsthenews]

Contacted a local engineer who's listed on Vaillant's website. Will update with further info'. Thanks again.