This has come up in a few threads so I thought I would give it a try and if it helps, make a quick how to for others to see.
Ok, so the CDI range isn't known as one of the easiest boilers to work on, the expansion vessel is fitted by way of a large cable tie right in the back end of the boiler.
In front of it, and subsequently what usually has to be removed in order to replace it, is pretty much everything. If you follow the manual, which I have done in the past you will soon find a long list of parts needed to be removed, including the main heat exchanger, fan, plate heat exchanger, pump, pipework etc and can be quite a long job, especially if the existing O rings leak.
So, providing you can access one side of the boiler, there is a much easier way of changing the vessel.
Start by removing the side panel, 2 screws in the front and one at the top
The lower panel in the above pic is what we are removing, but first a few things need to be removed to make life easier. Start with the stat wiring which sits up on the right hand side of the main heat exchanger.
Remove the 2 orange connectors (assuming you've already isolated electric etc) and pull them through the 2 grommets and tuck the cable away somewhere out the way under the boiler.
Next there are 4 screws which need removing, 2 in behind the PRV
The other 2 are behind this again and can be seen through the gap in the side panel, and accessed with a long pozi screwdriver
Next pop the white pin through to release the front fascia front the side panel, then release from the other side and let it dangle somewhere out of the way.
The only thing holding the side panel on now should be half a dozen rivets, these go through into the combustion chamber. Carefully drill these out making sure you don't go through the air pressure switch pipes in behind. I used a 4mm drill bit.
I left the main wiring cable (white) connected as there is enough slack to move the panel out of the way with it connected. Disconnect the expansion vessel tube from the pump connection and vessel, you can bin this as the new vessel comes with a different tube. Cut the cable tie and remove the expansion vessel from the hole.
The new vessel slides in easily without any fuss as you would expect, but I took a photo of it so I need to write something!
Reconnect the expansion vessel using the new tube supplied, sip tea, explain to the customer that it usually takes an hour and 5 bleeding knuckles to get this far. Quick :39:break, then;
Re-fit the panel, I then used pop rivets to replace the ones I had drilled out, the pipes to the right were in the way to get a few of the rivets back in, but make sure that all the rivets into the combustion chamber are re-fitted, for obvious reasons.
Re-fit everything in the reverse order and admire the fact it looks like no-one has touched it.
Thanks to the people who suggested this method, it could probably be done in 30 minutes if your not taking photo's along the way etc, took me about an hour all in, including changing the PRV which was stuck in due to a corroded retaining clip!
Hope that helps :grin:
Ok, so the CDI range isn't known as one of the easiest boilers to work on, the expansion vessel is fitted by way of a large cable tie right in the back end of the boiler.
In front of it, and subsequently what usually has to be removed in order to replace it, is pretty much everything. If you follow the manual, which I have done in the past you will soon find a long list of parts needed to be removed, including the main heat exchanger, fan, plate heat exchanger, pump, pipework etc and can be quite a long job, especially if the existing O rings leak.
So, providing you can access one side of the boiler, there is a much easier way of changing the vessel.
Start by removing the side panel, 2 screws in the front and one at the top
The lower panel in the above pic is what we are removing, but first a few things need to be removed to make life easier. Start with the stat wiring which sits up on the right hand side of the main heat exchanger.
Remove the 2 orange connectors (assuming you've already isolated electric etc) and pull them through the 2 grommets and tuck the cable away somewhere out the way under the boiler.
Next there are 4 screws which need removing, 2 in behind the PRV
The other 2 are behind this again and can be seen through the gap in the side panel, and accessed with a long pozi screwdriver
Next pop the white pin through to release the front fascia front the side panel, then release from the other side and let it dangle somewhere out of the way.
The only thing holding the side panel on now should be half a dozen rivets, these go through into the combustion chamber. Carefully drill these out making sure you don't go through the air pressure switch pipes in behind. I used a 4mm drill bit.
I left the main wiring cable (white) connected as there is enough slack to move the panel out of the way with it connected. Disconnect the expansion vessel tube from the pump connection and vessel, you can bin this as the new vessel comes with a different tube. Cut the cable tie and remove the expansion vessel from the hole.
The new vessel slides in easily without any fuss as you would expect, but I took a photo of it so I need to write something!
Reconnect the expansion vessel using the new tube supplied, sip tea, explain to the customer that it usually takes an hour and 5 bleeding knuckles to get this far. Quick :39:break, then;
Re-fit the panel, I then used pop rivets to replace the ones I had drilled out, the pipes to the right were in the way to get a few of the rivets back in, but make sure that all the rivets into the combustion chamber are re-fitted, for obvious reasons.
Re-fit everything in the reverse order and admire the fact it looks like no-one has touched it.
Thanks to the people who suggested this method, it could probably be done in 30 minutes if your not taking photo's along the way etc, took me about an hour all in, including changing the PRV which was stuck in due to a corroded retaining clip!
Hope that helps :grin:
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