BAXI 105 Fault Finding diverter valves and hydroblock in a boiler - Gas Training 

I could sit a listen to Roy talk about boilers all day the mans knowledge is second to none. What a asset he is to viva training!

Allan you’re a step ahead with the training. I hope you get recognition for your efforts. Best of luck pal.

What a fantastic breakdown and explanation of how these parts interconnect in a combi boiler. Thanks for the video🙂

One of the best explanations i have seen Roy..keep it up Allan

Brilliant Training Roy. Thanks for sharing Alan 👍

Love the 105 - so simple to service.

Thank you, Sirs. Both Allen and Roy. love every bit of it.

Thanks to this video I have fixed our Main 24he. We bought a property with this old combi in and wanted to keep it going a bit longer before replacing with something more modern. Our boiler wouldn't fire unless there was a large amount of flow from the hot water taps, requiring two taps to be opened almost all the way for the diverter pin to fully extend and engage the microswitch. I had removed the diverter valve body and fully rebuilt it using a rebuilt kit from eBay, but this made no difference. Watching your video, I then discovered the hydraulic Venturi. This was an even bigger faff to remove, but eventually got there with a 24mm wrench. The plastic part had disintegrated and the spring was loose in the hydroblock. I fished it out and replaced it with a new £15 replacement from eBay and now the boiler works as intended. Surprisingly none of the gauze filters were blocked on this old boiler and everything was quite clean. I also removed the differential pipes and flushed them out with water and air. I have degrees in mechanical engineering and electrical engineering and currently work on designing building control systems, but I will be having a gas safe engineer come and check everything over before we move in to the property. Cheers.

another great video Roy is a good lad had him train me when i went down to Baxi

Brilliant, loads of useful info, cheers

Excellent video! Seemed like I’ve actually sat in the training classroom 😀

You talk a language I understand. Great video and thanks doing it. I just wish I watched it before I spent hours repairing a main 24 he yesterday....it would of saved me a lot of time. ☺

Brilliant video, I'm a breakdown engineer and learned a couple of things here 👍

I’m in awe of your knowledge . When I was working combi boilers only came in half way through my career they were and still are more trouble than they are worth just so many things that can cause problems

Fantastic video, great explanation of the operation, excellent. 👍👍👍👍🇬🇧

Great training, thanks chaps.

As usual, 💫💫💫💫💫 can't find better teaching than this 🌹

Brilliant video Roy. 👍

Always great videos, Many thanks

Well done lads very informative, thank you 👍

Cracking video Allen cheers

Roy, you are a genius. 10/10. Not only an expert with vast experience, rare ability to explain and make it understandable to ordinary viewers. I know the video is for trainee engineers but ordinary householders can understand the workings and complexity of diverter valves.

Another great video, keep them coming

thanks Alan and Roy very helpful video

Great video again.

Mate you doing a great job. God bless

Great video, well explained. Cheers

Great video all the info and tips you require to know

Great video, fantastic. thank you for that splendid work sir.

Excellent video. Very good explanation.

another great video Alan. loving the channel and content its proper interesting your a top bloke mate

Cracking video here guys 👍

Great video lots of good information again quality

Thanks the filter in the return seems to solve my problems 👍

Great video.

Cracking video 👍

Another good video.....Thanks Allen......U Dah Mannn !

Wonderful video

Very useful suggestion on ensuring the small pipe off the rear mounted bypass which feeds the pump proving diaphragm and associated microswitch isn't blocked. Great video.

Great vid 👍🏻

thanks you explain very good.

Thanks allen 🤩🤩🤩

Thank you very much.

Great video I would like to ask it will part numbers for metal washer for thermistor, water flow restrictor

Found those filters on a potterton I believe it was... almost made me cry, I'd spent that much time messing about with other things 😄

Hi Allan you are great explaining in deep depth. on my Bexi duo tec it take long time to get hot water going when heating is off. what could be be the problem? manohar

Thank you 👍

Excellent content Roy, Allen and viva training. I always felt that baxi got it wrong with the GA range boilers. I have a pet hate for them, dislike working on them.

The hydraulic Venturi can be difficult to remove. You need a 24mm ring spanner and it helps to spray it with shock release spray if it is stiff to loosen it up so you don't round it off. If the plastic part has crumbled , you can get the pieces of plastic out by removing the plate and poking the plastic out from the back. Also check in the plate for pieces of the plastic.

Great in depth video and learning new things Love knowing how things work and the cut down parts so You can see inside Also I’ve changed a few diverter valves on these boiler an a few times I’ve had the orings on the bypass leak.. Tried replacing for one of my kit box but nothing near correct size, Baxi do sell them but they don’t give you the actual size of the orings . I found thus awkward as you cannot replace this oring because not knowing the size.. would Roy know the size of the bypass oring ? Thanks

Great explanation Roy. Would you happen to have a cutaway of a 105 Instant diverter valve. That would be equally useful.

Thanks for the video Alan. Can I use a 14mm socket to get that dhw venturi out

Great video 👍. Where can I find the list of part numbers?

great knoledge

Great video Allen thanks

Could do with a breakdown of each of the service kits for this hydraulic section with part numbers. Any chance of revisiting this training video and adding them?

Great video as usual. Roy is the man on the 105’s. the brass washer for the thermistor instead of the fibre ones provided anyone know the part number for it?

The small O ring at the back of the differential valve some time leaks, also. There is, a new one in the service kit. Which is sometimes over looked!

Hi great vidio. I have a baxi105e and had no hot water just change the heat exchanger and fab hot water. But one hour later no hot water. Any help would be appreciated cj

Brilliant video. Very knowledgable. Can you give me some advice on my 105 please? The pressure keeps gradually rising. It doesn't rise when doing nothing. The flat plate has been renewed 6 month ago so isn't pinholed or shouldn't be.The ev is ok. The pressure rises each time hot water is used, so after a couple of days using hot water the pressure is right round and overflowing outside. Thanks. Hope I'm not in for a hefty repair bill😂

Great video Allen and Roy, May I ask as Roy never mentioned it, what would cause the pin on top if the diverter valve not to fully retract after demand, I have an issue where after pump has stopped the pin is half way out and still engaging the micro switch Many thanks

What could be the culprit of the plunger not coming out enough of the pressure differential valve on the front of diverter valve for hot water. It comes out a little bit but not enough to activate the microswitch. The plunger and diagphram have been replaced with no avail. The hot water does work but only with the heating on.

Hi there got a main combi 25 got a problem the pump proving pin is continuously up and runing the pump I have changed the diverter valve the whole part but got the same problem I hope u can give me some idea ?

Hi, have one at the moment, hot water is temperamental, but when there’s a call for hot water the pin on the heating side doesn’t retract, the pin on the water side comes out, Boiler fires up but hot to start then goes tepid, pin on heating stays engaged with micro switch, any idea please

I have a Baxi Duo-tech 28 HE A. It’s working okay, no fault codes etc. Located in a downstairs utility room. It feeds the radiators upstairs and them drops down into the lounge and onto the hallway. All the radiator upstairs get hot and the hot water supply is fine. However the radiators in the lounge and hall do not get any heat. i’ve checked and there are no blockages. The boiler has just had the DIVERTER cartridge, motor and thermistor replaced. but this has mad no difference. Any ideas what could be causing theirs. The boiler has been installed for 11 years.

Hi, could you post the hydro inlet assembly filter and flow restrictor part number 12 L. As Baxi parts don't list this individually, only the full unit? MAIN 24HE HYDRAULIC INLET ASSEMBLY 248246. So how can just the required serviceable items be obtained?

Hi Alan just been called out, heating not firing, pin not coming out of block, changed diaphragm, power off as system comes up to pressure pin comes out and makes contact on microswitch, asked everyone no recommendations, changed diverter valve system works everything fine now but why did pin come out after diaphragm changed

I cleaned everything like new every piece is cleaned and waxed good water pressure the membrane is good but the hot water pin is not coming out to activate hot water mode with my hand it moves perfectly but with water the pin doesn't come out

Radiators are getting warm when hot tap is running main 30 He ?

ON THE BACK PART OF THE DIVERATOR IF THE PIN IS STAYING UP, THIS AFTER REPLACING A NEW DIVERATOR ON A BAXI 80 ECO...WHAT IS THE PROBLEM..THANKS

Hi allen another great informative video throughly enjoying roys boiler training its very helpful, is it possible to do one on the hydro block for the baxi instant combi he version its the one where the expansion vessel is used for pre heat would be superb if you could thankyou

so what is the problem if you only get tap hot water when the radiators are on

Why do I only get hot water when heating is also on .

Hi , i have a Baxi 105 HE , had a problem for some time with only getting hot water if the mixer tap is turned on full on all taps and it takes about 1 minute to get hot, as soon as you reduce the tap the burner stops and cold water , could you advice on what the problem could be, the plumber has changed the diaghram on the diverter, he saying now the diverter is faulty, would appreciate your help, thanks

Is the rear plunger meant to come up when the DW plunger hits the switch?

👍😉

Thanks the video, could you have me the spare part kit number?

Question ? Running hot water tap radiators getting warm what is this please

looks like the part numbers promised at 12.min 50 on the video never made it, rather disappointing guys