Baxi 105e: Leak after replacing plate-to-plate heat exchanger

[raidwi]

As per title, have replaced the plate to plate heat exchanger on a Baxi 105e.

After fitting the replacement and putting everything back, upon restoring the domestic water supply there is a leak out the right-hand-side of the heat exchanger.

The heat exchanger was purchased from eBay with has the right part number on the listing, but the four holes are slightly smaller than the original I removed. It came with four new rubber seals, but the old ones were stuck firmly in place, it has never leaked to date, and in any event couldn't be removed so I was happy to leave them in place.

It just doesn't seem to be making a tight seal, so it feels like I'm missing something obvious. Would be very grateful for any tips those who have replaced these before could provide.

 

[CountryFan]

It came with four new rubber seals, but the old ones were stuck firmly in place, it has never leaked to date, and in any event couldn't be removed so I was happy to leave them in place.

It just doesn't seem to be making a tight seal, so it feels like I'm missing something obvious.

Seems fairly obvious to me

 

[raidwi]

Seems fairly obvious to me

It's why it's not making a tight seal that I'm struggling with. The screws are in as before, the seals are in the hydraulic inlet as before. The seals don't stick out of the hydraulic inlet, so the heat exchanger is just sitting flat against it. I will try and see if the new seals stick out a bit so there's something to press and seal against.

 

[gas112]

The seals are a wee bit awkward to get out a bent pick is handy for them
out of the countless plates on 105`s i have had in and out i have only ever had one original seal leak so you are a wee bit unlucky
You could try a bit of silicone grease onto the existing seals see if that works

 

[raidwi]

Seems fairly obvious to me

The seals are a wee bit awkward to get out a bent pick is handy for them
out of the countless plates on 105`s i have had in and out i have only ever had one original seal leak so you are a wee bit unlucky
You could try a bit of silicone grease onto the existing seals see if that works

Thanks both - the new seals did stick out a little, and so sorted it. Didn't have any silicone grease but will pick some up the next time I'm in Screwfix