Ecotech - Pressure issues

[FNG]

hi,

Having intermittent problems with our boiler, going to call out an engineer but attendance/fix is days off due to availability and them all being busy and wondered what people think

Capture

• FNG
• 18 Mar 2018

Boiler

* not a photo of my actual boiler, this is a stock photo from the web but it's accurate enough

Essentially it looks to be a pressure problem.
I have checked the system and there are no leaks.
The condensation pipe and overflow pipe are fine

I get the F22 error occasionally

When the error is in place the boilers main burn won't come on for either water or heating

Looking at it I can see that the pressure gauge on the right when it errors is showing no pressure. But if I try and fill it it, it does rise but the system goes nuts.
Pressing the "-" button on the console gives me a pressure which is between 2.5 and 3ish and higher if I have attempted to raise the one on the right.

So the two pressure outputs are clearly very different

Is it likely one is broke or are they measuring different things?

Is this problem likely to be linked to the expansion tank as I suspect the expansion tank needs recharging (and checking for faults). I've seen threads on doing this but I don't have the confidence to drain the boiler seperate to the system, I don't have a suitable pressure gauge and I would rather get an engineer to check in the likely event my diagnosis is crap

Thanks for your ideas

 

[FNG]

currently running, gauge on the right has kicked in and up about 1/3.

digital display was showing 3.2 but I took a smidge of water out of a radiator and it dropped to 2.4

I assume that increase on running is due to expansion tank not working as expected as the water heats up

 

[terryplumb]

If you are losing pressure ,then F22 indicates too low a pressure and boiler will not fire. Water is being lost from the boiler ,or the system. The analogue gauge and digital displays both relate to the system pressure and slight difference isn't a worry ,but large differences indicate a problem. When cold the pressure should be circa 1 bar ,and when system is hot water expands and pressure increase is normal ,however anywhere approaching 3 bar is indicative of a problem with EV. PRV should lift at 3 bar.

 

[FNG]

so both pressure measure the same thing? Do they do anything different or is one just a crappy basic visual thing for home owners?

can't see where water is being lost from
checked all the rads, checked under the house, checked the ceilings, checked the outside where boiler is, can't see anything
also once its running it runs fine without need for top up so any leak is drips at most

PRV is the pressure release valve, whats EV?

 

[terryplumb]

EV ( expansion vessel ),linked to what you call overflow pipe. Any signs of water coming out of it ?

 

[FNG]

A smidge here and there but not a huge amount and not constant

 

[FNG]

Yup, it carked it again whilst I was at work.
When the heating is off for a period it then refuses to come back on as I assume the pressure drops as the water cools
F22 error, 0.2 bar pressure

To coax it back to life
I open the infill valves and let barely a splosh of water in to raise it to like 0.5 bar and the main burner will kick in as soon as the safety thresholds are passed
I close the valves and the pressure continues to rise as the system water heats up.
Within 5 mins it's up to 1.5 bar but this is all on the digital display. The analog display is still at zero
Within 10 mins it's up to 2 bar and then I just need watch to make sure it doesn't get to 3
If it's looking around 3 I let a smidge of water out via an easily accessible radiator system drain value

boiler people can't make it till Thursday which is frustrating as if it's just the EV needing recharging I assume that is a 1 hour no parts job for a person who knows what they are doing and has the right tools

 

[Daveydub]

Choose a radiator that you can live without. Turn off both valves on the rad & drain the water out. Turn one valve back on & the air in the radiator can be your temporary EV untill engineer arrives. Sounds like your analogue gauge is blocked

 

[FNG]

Right, taking the system as fully cooled and not working due to low pressure
I have partially drained the radiator in the loft as it's the warmest room
Drained it by simply letting water out of the system at a ground floor radiator which was easy enough
the plan is that the top radiator is the easiest to get the air out of so once resolved topping up the system will be a doddle
I then opened the air valve on the partially empty radiator to get air in there.

Once that was done, I sealed the system and put water into it till the digital pressure was showing about 1 bar and the system kicked in and heated.
Heated the system to where it caps out and then topped it up again to about 2 bar in pressure

System is currently running fine with pressure going between 1 and 2.5 bar from stone cold for hours to running at near maximum for a while

Engineer is due tomorrow morning so hopefully the expansion tank is working but just needs to be recharged (BTW, would a service check the expansion tank pressure as it was serviced not long ago).

Thanks for the tip on using the radiator as a temporary expansion tank

 

[FNG]

boiler engineer turned up

recharged the EV and refilled the half empty radiator and this seems to have fixed everything

The analog pressure gauge is knackered and they asked if I was interested in replacing it of if I could live without it?
I am living without it

thanks for your help on this