Diverter valve problem.

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Green_Machine

Green_Machine

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Hi.

I am having an issue with a baxi 105he. I want to refurb the diverter valve as we are having issues with HW..

I have isolated the cold water feed into boiler drained the primary system "rads" even though this is not needed drained the boiler turned the hot taps on upstais downstairs still mains pressure coming out hot taps. Now the HW is always been shocking and had diaphram changed 3 years ago.. I seem to remember I had same issue then.. I replaced the fill loop isolator yesterday as was sticking I took off the main isolator for feed to boiler checked it working fine.. as it was on tuesday when I tried to replace the thermistor there is still mains pressure feeding the boiler coming in the hw outlet thats the only thing I can think of.. I can turn off the mains to the house and it stops as I had to quickly do it other day to stop disaster.. Its doing my head in because I should not have to turn mains off to change this out.. Pretty sure there should not be mains coming in the Hw outlet on boiler. What is the issue is it dodgy pipework because the guy that owned house before us was a cowboy so much dody stuff.. I can do the job by turning off mains water but whats the point in doing the job if that is not only problem.

Anyway any advice other than get a gas safe guy in..
 
Hi.

I am having an issue with a baxi 105he. I want to refurb the diverter valve as we are having issues with HW..

I have isolated the cold water feed into boiler drained the primary system "rads" even though this is not needed drained the boiler turned the hot taps on upstais downstairs still mains pressure coming out hot taps. Now the HW is always been shocking and had diaphram changed 3 years ago.. I seem to remember I had same issue then.. I replaced the fill loop isolator yesterday as was sticking I took off the main isolator for feed to boiler checked it working fine.. as it was on tuesday when I tried to replace the thermistor there is still mains pressure feeding the boiler coming in the hw outlet thats the only thing I can think of.. I can turn off the mains to the house and it stops as I had to quickly do it other day to stop disaster.. Its doing my head in because I should not have to turn mains off to change this out.. Pretty sure there should not be mains coming in the Hw outlet on boiler. What is the issue is it dodgy pipework because the guy that owned house before us was a cowboy so much dody stuff.. I can do the job by turning off mains water but whats the point in doing the job if that is not only problem.

Anyway any advice other than get a gas safe guy in..
 
Green_Machine said:
Hi.

I am having an issue with a baxi 105he. I want to refurb the diverter valve as we are having issues with HW..

I have isolated the cold water feed into boiler drained the primary system "rads" even though this is not needed drained the boiler turned the hot taps on upstais downstairs still mains pressure coming out hot taps. Now the HW is always been shocking and had diaphram changed 3 years ago.. I seem to remember I had same issue then.. I replaced the fill loop isolator yesterday as was sticking I took off the main isolator for feed to boiler checked it working fine.. as it was on tuesday when I tried to replace the thermistor there is still mains pressure feeding the boiler coming in the hw outlet thats the only thing I can think of.. I can turn off the mains to the house and it stops as I had to quickly do it other day to stop disaster.. Its doing my head in because I should not have to turn mains off to change this out.. Pretty sure there should not be mains coming in the Hw outlet on boiler. What is the issue is it dodgy pipework because the guy that owned house before us was a cowboy so much dody stuff.. I can do the job by turning off mains water but whats the point in doing the job if that is not only problem.

Anyway any advice other than get a gas safe guy in..
Click to expand...
Top tip,,,if you drip so much as a few drops of water on the PCB it will knacker it.
 
There shouldn't be water flowing through the boiler with the mains to the boiler switched off, the usual suspect is a passing shower mixer or kitchen tap, can you isolate the outlets in your house ?
 
As @picasso says, probabl a shower or mixer tap blending aand you are getting cold mains water coming back fro the hot outlet, you say that you have been having HW problems, this could be the same cause, other thing is cold and hot pipes connected the wrong way round, a lot more common than you would think
 
Thank you for the replies.. Yes in end I just turned the mains off. refitted Diaphram greased spindle and reinstalled.. I have a few more bits coming tomorrow to rebuild the valve. Yes I think it maybe the shower that is screwed. I will take a look also. I do think cold may have been tied into the hot outlet somwhere behind the trainwreck of kitchen units and plumbing. Integrated dishwasher that is Siliconed into the wall with no access there is some very suspect pipes coming from the Hw outlet leading behind it. A extension with 2 dodgy rads in it and a downstairs loo. One of the walls in the dodgy extension is made of insulation boarding screwed onto windows and boarded up on the inside its mental.. Anyway thanks for advice. Will get back on it tomorrow can get enough hot water for a shower tonight atleast. Definatly too much pressure going through system. Will probs do the venturi valve at same time.

Will let you guys know how it goes.
 
Turn the CH on till it is quite hot, then open a hot tap and feel the two HW inlet and outlet pipes below the boiler and see which one gets hot first
 
Update deffo shower allowing cold into Hw system.. no isolators with access on the pipes leading to it none under bath absolute nightmare its a fully tiled bathroom with the shower in the corner of an outside wall so no access behind, the temp mixer is seized.. to hell! noway turning it need a need new shower its nackered.. managed to get the faceplate off only thing in whole house actually fitted correctly could not get the frigger off no isolators on pipes behid can't get to them without smashing the tiles.. There was 2 iso's on the shower itself phew 1 seized stripped the flat head off. Managed to screw the other in was the cold!!... Boiling hot water from taps all round house happy days.. I bet now will be able to drain boiler tomoz no problems without shutting mains off.. here's hoping! still going to referb diverter and do a few other bits. Rip out dishwasher check all other pipework see how it goes.. I had an Idea it could be somthing to do with that shower never believed it could be passing through so much pressure..

Thanks guys will see if its solved tomoz.
 
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