Glow Worm Boiler Problem - SOLVED! Seized 3-port valve.

SaabmanBOF

SaabmanBOF

SaabmanBOF

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Joined
3 Feb 2014
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39
Good morning everybody. I have a problem with my Glow Worm Flexicom 18 SX; it only fires up if the hot water circuit is also calling for heat. Once fired up, the rads heat up as normal, until the hot water is up to temp, when it shuts down. Pressing the minus button for five seconds brings up codes 5 and 30, neither of which is in the decode list.

Is this something I can fix myself, or (probably...) is it time to send for a pro?
 
Thank you for that; I should have been more exact. The problem doesn't seem to be an overheat malfunction, though. I don't get F5 or F30 displayed, just the figure 5 then the figure 30, alternating, and the boiler isn't actually locking out; if I turn up the temperature on the hot water 'stat on the tank, it fires up and runs OK. If I was using lots of hot water, I might never have known I had a problem at all...
 
Are you sure? The problem isn't with the distribution of the circulating water, it's that unless the hot water cylinder is calling for heat, the boiler does not fire at all. I can't see how the motorised valve would affect that.
 
NOW I understand! Thank you again.

It's a Honeywell 40004805-001, a 3-port.

There's no sound of movement within it when I turn the boiler power on or off; I've given it a few sharp taps with a hammer, but that made no difference. It makes no difference whether the control lever is set to auto or manual, either. I guess I should just go ahead and replace it?
 
Thank you again; that is very helpful. I presume actual replacement of the motor is quite straightforward, but can I easily remove the silver box from the valve assembly with the valve assembly in situ, or will I need to have the whole thing on the bench?

STOP Press: Found it on line. Easy Peasy... I have the lid off, and the round motor casing is very hot, so I presume it has seized. I'll sort it as soon as I get a new motor.

Note to self: remember to turn off the power to the boiler before doing the job...
 
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I have replaced the synchron motor (awkward for access, but very easy otherwise). It still doesn't work. ******! There is a slight change, in that if I select central heating only, the pump runs for about half a second, then cuts out. All else is as before; I still have no F codes. Double ******!!

Where should I look next, or should I give up and send for an engineer?
 
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No need, thank goodness. It must have found out I was threatening it with a multimeter; I tried it again an hour later, and now it is working normally again! Let's hope it keeps doing so...

Thank you again.
 
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