Baxi Combi Instant 105 HE Diverter Valve leaking - HELP!

14 Feb 2009
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United Kingdom
Hi Folks
I'm new to this forum but hoping you can help me.
My Baxi Combi Instant 105 HE boiler is leaking central heating water from under the Operating Head of the Diverter Valve assembly. I've removed the Operating Head and it was full of central heating water! The leak stops with the Operating head removed and when I stick my finger into the top of the Diverter Valve assembly and push the push rod, central heating water pours up and out of the top of the Diverter Valve assembly. Is there an o ring that seals this push rod, and if so, how do I get to it to replace it?
Hope you can help?
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To Steven:
What was the solution to this in the end?

To Everyone:
I have the same problem, and am hoping not to have to replace the entire diverter.

Unless I'm confused, all the threads I've found on this forum about baxi diverter valve leaks are to do with the dhw flow gland, not the operating head bit... or have I missed something?
Hi tj123
The leak got steadily worse and I replaced the Diverter Valve body. Not too bad a job but I had to go out and get fibre washers that did not come with the valve. The operating head valve rod gland was definitely at fault and seems unrepairable even with the old diverter valve removed. It was leaking out of the operating head with me blowing into the diverter valve, holding my fingers over the other connection and operating the valve rod by finger.
Like you, I could not find another thread that had this kind of leak but the solution is clearly to replace the Diverter Valve.
I took a photo before I started so I had a reference point. The photo shows my leaky Diverter Valve.
if you drain the boiler and remove the head you can unscrew the top of the valve and replace just that part no need to replace the full valve, prob is normally caused by poor water quality
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As Gordon siad the gland is replaceable by one of the alpha 240 kits.
Useful to know but all a bit too late for me. I sourced the complete valve for £35 so I am quite happy. The water I drained off was very grotty indeed, supporting gordongas's theory on cause. I flushed the full system opening each rad in turn for 4 minutes and have put in some cleaner to run through for a couple of days.
I couldn't track down a diverter valve kit that would fit - interested to know the part number of a suitable kit.
I got mine from ebay. It was for a 105HE Instant Combi.
You might want to follow up on the repair suggestions. I couldn't dismantle mine and lost the will to try particularly had when I had removed it. It must be possible to get into the valve body.
Good luck
You just remove the clip and lift off the motor then undo the nut part with the slots!

I can supply a brand new kit for £40.25 plus postage or you can pick it up if you are anywhere close to the central belt in Scotland.
The kit includes D Valve Head with seal, D Valve base with seal and retainer, pre assembled top valve with spring and seal, lower valve with seal and mid spring - all new and unused.

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