Open vented system, No HW or CH, BAXI 80HE boiler shows Ignition Lockout after tried to start a few times

[fandyman]

Sure see attached.

Thanks.

 

[Johntheo5]

Thanks but I should have asked you to photo the info right on top of the pump, there is a lot of info on the black portion behind where you took the photo, you can see it in the original photo of the oump.

 

[fandyman]

Ahh ok makes sense and no worries. See attached.

 

[Johntheo5]

OK, found it, CC2 @ 20W is circulating 0.6m3/hr,10.0LPM but @ 13W is circulating practically zero to the HW coil, maybe ~ 0.1/0.15m3/hr, 1.7/2.5LPM. Is there a wheelhead balancing valve on the cylinder coil return, if, might be throttled right down, or could be a airlock, if you slacken back the compression nut say 3/4T on the top coil pipe at the cylinder and pull it back see if you get any air/water out.

Also, or maybe first, with HW only selected, pull on the manual lever on the MPV, you should feel a immediate resistance on pulling it across.

 

[Johntheo5]

Because you said both pipes were hot in a earlier post maybe remove the MPV head turn the valve spindle manually to HW only (port B), select HW only and see does the boiler fire and check pump power W and feel the coil flow and return.

 

[fandyman]

Yes sorry just catching up. I'm out of house at the moment but I did remove the MPV head few days ago and set the spindle manually to each position. It did not seem to make a difference to the always equally hot A and B pipes. Did not check the boiler firing in HW only and will do when I am back. The pump was showing 20W in CC2 and 45W in CC3. That was mostly tested with spindle in the mid position though.

I will do the tests when back - thanks!

Do you think the valve body may be faulty as I cannot remember the time one was hot but not the other since I moved in 2 years ago and I had quiet a few of these issues already.

 

[fandyman]

For the wheelhead balancing valve I can post few photos when I am back but I do not remember seeing any.

As for the slackening back the compression valve do you mean when the system is hot? Currently cylinder is showing about 50C when it clicks.

 

[Johntheo5]

If the cylinder is heating up with the valve in mid position then its hardly a coil problem? but would have thought that turning the valve manually should give HW only, HW&CH, & CH only, its possible of course that the ball has become displaced or something like that but unusual, maybe try it again with head removed, valve turned to HW only and HW only selected, if the boiler doesn't fire up, let the valve in the HW position only but select HW & CH, ensure the roomstat is calling and see does the boiler then fire up, check pump power.

I wouldn't bother with slackening the compression nut just now.

You should get ~ 20W on HW only, I get that if I run my Wilo at the same pump head as the Grundfos on CC2.

 

[fandyman]

Thanks for your help @Johntheo5.

Ok so I did this test:

"...maybe try it again with head removed, valve turned to HW only and HW only selected..."

the boiler stayed on and the pump reading on CC2 was 16-17W.

then I did this test:

"...let the valve in the HW position only but select HW & CH, ensure the roomstat is calling and see does the boiler then fire up, check pump power..."

the boiler stays on and the pump reading on CC2 was 20W.

What I also checked was whether the strong magnet attracts around pump and 3 port valve and it does in a lot of places including 3 port valve but not on the B side - just A side, the valve and below the pump (see attached).

 

[Johntheo5]

CC2 @17W = 0.52m3/hr, 8.7LPM and @ 20W = 0.62m3/hr, 10.3LPM. Since the valve can't have changed position then I think those two readings are OK, my cylinder coil normally circulates at ~ 10.0LPM.

Can you test now with the valve manually turned to CH only (port A) and fire the boiler with CH only selected, roomstat calling, if it doesn't, fire it way you can, you only want to see the pump power/flowrate on CH only. (Back in hour or so)

 

[terryplumb]

Is the boiler / full system now working as it should ,or is the boiler still going to lock out ?

 

[Johntheo5]

CC2 @17W = 0.52m3/hr, 8.7LPM and @ 20W = 0.62m3/hr, 10.3LPM. Since the valve can't have changed position then I think those two readings are OK, my cylinder coil normally circulates at ~ 10.0LPM.

Can you test now with the valve manually turned to CH only (port A) and fire the boiler with CH only selected, roomstat calling, if it doesn't, fire it way you can, you only want to see the pump power/flowrate on CH only.

If you are not getting a reasonable flow with CH only then there's at least one problem, if OK just put the valve manually to mid position and note power/flowrate.
Then suggest boxing it all up and do the three tests, HW only, HW&CH, CH only via the programmer and compare with the manual settings.

 

[fandyman]

I did put programmer to CH only, change the spindle of the valve manually to CH only and room stat calling for heat fires the boilerup but stops at some point and goes to stand by. The pump shows 18W.

What is bizarre is that when I switched the spindle manually back to HW only (everything else the same) I got a lot of vibration on the pipe work and initially the pump showed 14W. After bleeding the vent next to coil it went back to previous 16W.

When I change to mid position with everything the same it is still 18W like in CH only and boiler fries up too.

All above are CC2 on the pump.

@terryplumb like like no ignition lockout error on the boiler for 3 days now.

 

[fandyman]

I will box it up now and post later today.

Thanks

 

[fandyman]

Ok so I boxed it all up and redone the tests:

1) HW only - boiler runs for 30sec or so (probably from previous mid position) and stops even though cylinder stat cranked up to 70C before the test, pump shows 18W
2) HW & CH - boiler fires up and runs indefinitely when room stat cranked up to 27C, pump shows 19W
3) CH only - boiler fires and runs indefinitely when room stat cranked up to 27C, pump shows 16-17W