Vaillant Ecotec plus 831 - swapped diverter valve, now no CH

The flow and return service valves are open when the line marking has the same direction as the pipe.

They were open, but I have success anyway - I switched boiler off, and then turned off all the TRV's on all but the bathroom rad, plus one other. I was then amazed to feel heat drawing up the pipe toward the one other rad I had on. I waited until that rad was completely hot before turning another TRV on another rad on, and one by one they are all on.

Not sure what relevence doing what I did had - but I have success anyway - Cant help feel I still have air in there somewhere tho.

Thanks to everyone who has had an input in this long journey - but its looking good so far.

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Hi everyone, I know this thread is three years old but I have a leak from the spindle coming from the diverter valve on my three year old Ecotec 831. It's clearly CH liquid as it is yellow from the X100 which I added after trying to solve my cold rad issues with X400 a couple of months ago. Strangely the leak started two weeks ago just a few days after a plumber doing my gas safety cert increased the pressure by 40mbar (4 full turns clockwise of the bypass valve) after I told him I was having issues with getting all rads on (symptoms on rads were some hot inlet valve and cold outlet valve with valves open and some just fully cold with others just warm). Hours spent balancing never got them all on! With the poor rad performance from day one of commissioning when the house was bought from new, I suspect the 10mm John Guest Speedfit off 15mm John Guest Speedfit designed system (with some drops from the first floor to ground with the boiler on the ground floor in a three storey property) is the problem with the rads!!! And how very strange it is that the plumber who 'designed' the system isn't keen to view his own work...

My actual question is whether the diverter valve can be serviced on these as I had the same problem on a Worcester Bosch 24CDi and I managed to replace the little 0-rings for similar size for about 20 pence five years ago and they're still holding firm! I could check this visually on the Ecotec DV but would rather have a heads up so as not to take the DV out twice if needing a new DV.

Also, if anyone has any input on the rad issue and whether adjusting the bypass would have helped/caused the leak that would definitely be of interest!!!
Hey guys, can anyone offer me any advice on my previous post? Any comments from the professionals will be greatly appreciated!
No screwing the bypass would not have caused your leak. And no there is no service kit for ecotec divertors .
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Thanks Bunnyman, I took out the DV and a load of black debris came out so I gave the DV a good wash out and Vaselined the spindle (and slid it in and out a few times) and the leak has, for the time being stopped so I guess a very small piece of debris may have crept between the spindle and O-ring to break the seal as it's only three years old so doubt the O-ring has actually failed.

I've had a look at a few threads on here and I think I'm going to add a filter and run through some X800. Does anyone think this is a bad idea with an Ecotec Plus 831 fitted in Jan 2011 and would two bottles be a good idea for X800 then X100? I'm hoping this will improve the very poor performance in my three storey 13 rad system. Meticulous balancing has never got all rads on even after running through some X400 and as I mentioned earlier I think the speedfit 10mm off 15mm speedfit is the underlying issue. The fitter even directly pulled a rad off from the flow about 30cm from the boiler for the lounge (the only rad that ever got too hot to touch) which I leave fully off to help the pressure in the rest of the property.

Does anyone have any positive feedback on which filter to use? It sounds like magnetic with a mesh filter makes sense, are they all designed this way?

I'm determined to get this system running well, it's so frustrating that a three year old house has never been close to having all rads glowing hot!

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