We often come across an older boiler within a house where the flue runs through an existing chimney. Many customers have been told that a modern condensing boiler can’t be fitted in such a location – but that is usually not the case.
Somewhere near Gatwick (customer confidentiality means we don’t ever say where a domestic residence is located).
What their installer means by saying it can’t be done is that they either; have no experience, don’t know how it could be done, or simply can’t be bothered.
Using an existing chimney does, in almost all cases, require the inside to be lined with a stainless steel or plastic liner, replacing the existing chimney liner. It also (unsurprisingly) requires us to access the chimney pot across the roof – all these things can make the use of the chimney a more expensive option.
However there are circumstances where this is the only option of interest to the homeowner due them wanting the boiler to remain in the current location, or perhaps it is a listed building and the conservation officer will not allow the boiler to be resited elsewhere.
Today, our customer had an old Perrymatics Wallflame boiler which had lasted around 40 years, but was now up for replacement. It had been built in a purpose designed compartment within the kitchen and used a brick chimney flue to the roof.
Perrymatics oil boiler, about to fire for the last time.
We were asked to resite a new Worcester Danesmoor utility condensing oil boiler in the cupboard, which meant running a new Worcester Flexiflue system up the existing chimney.
Note lovely Danfoss Randall timeswitch, also destined for the skip. These might be collectable one day.
Under new guidance from OFTEC, we are required to make flue joints accessible for annual inspection, so in this case we had to construct a fire resistant box under the soffit to encase the flue liner and allow visible checks.
New fire resistant box and inspection plate, together with flue specification plate.
The Flexiflue within the chimney in continuous and therefore does not require inspection.
Liner ready to go down.
The tops of most chimneys look like this. Moss, cracked cement and loose bricks are the general norm.
Our roofer took out the old liner and then we cleaned the inside of the stack, followed by inserting the new liner from the roof.
We converted the system to a ‘fully pumped’ type which involved replacing the old ‘gravity’ hot water cylinder with a new Gledhill Envirofoam unit, together with a new Grundfos low energy pump.
Pictured prior to pipe insulation being added.
Finally we replaced the old Danfoss Randall timer with a modern Honeywell ST9100C HW timer, and the thermostat was changed to a Honeywell CM907 programmable unit. This was a job where we didn’t fit Evohome!
New Honeywell timer.
With a 7yr warranty on the boiler, our customer was very happy.
This is the fourth boiler replacement we’ve carried out in this particular road, due to recommendations.
Our customer with his new boiler.
Why not view our main page about our boiler installations in Surrey which includes lots of other interesting case studies?