Condensing boilers are only a cod

E

eamonn123456

Registered User
Messages
483
That's what I have just been told by a local heating engineer.

He says that they don't condense when they operate over 50 degrees.

He says they are only efficient 'for the first hour'.

He reckons they are only useful for underfloor heating which runs at lower temperatures.

He says that, given their higher cost to purchase vs a 'traditional' boiler, they are a waste of money.

Totally confused now.

Anyone agree?

[oil boilers by the way]
 
Last edited:
I disagree.

You installer is kinda half right, or I should say has half the facts.

The return coming back from heating should be between 50 to 60 degress to allow condensatation to occur you flow going to the heating should be 20 D more.

It is unlikely your system temperture would be 80D(return temp of 60 and flow temp increase of 20) regardless of lenght of time heating is on. The return will (shoul) be in the 45-55D range.

It is very important system is balanced. and temp differance is maintained.
 
OK thanks for that, I think I get it.

Do you think are these boilers more expensive to maintain / get serviced , and are they more likely to go wrong i.e. is the total cost of ownership higher than a traditional boiler?

Or, do you reckon they are the way to go, as long as they are installed and set up correctly and maintained correctly?
 
eamonn123456 said:
OK thanks for that, I think I get it.

Do you think are these boilers more expensive to maintain / get serviced , and are they more likely to go wrong i.e. is the total cost of ownership higher than a traditional boiler?

Or, do you reckon they are the way to go, as long as they are installed and set up correctly and maintained correctly?
Click to expand...

Here's a picture that may explain the workings of the boiler better www.energyagency.org.uk/admin/ktmllite/files/uploads/Condensing Boilers.pdf. the lines on the return heat exchanger is flue gas.

Probably more expensive to service by some, a few gas boilers in particular have to have seals replaced everytime it is serviced or whenever burning chamber is accessed.

I have only ever fixed one condeser and it was because it hadn't been commissioned correctly/at all.

Yes I belive they are the way forward. When I build, I will fit an oil condenser.
 
They ARE more efficient.

Flue gas temperatures for standard boiler range around the 200 deg range,
so if you consider a HE condenser boiler flue gases range from 40-80 deg,
well you can see instantly you have a saving! as less heat is being chucked out your flue into the atmosphere.
(condensing only happens at below 55 deg, known as the due point)

And furthermore, is we are talking about a gas boiler, these are not only more efficient due to condensing, the HE boilers also modulate to required load reducing the most in-efficient operation of boiler (ie, ignition & shut-down) they are also considered 'turbo-charged' (ie, gas and air are mixed via a modulating fan before ignition, unlike standard appliances) making the burn cleaner and more efficient.

And lastly, since April 1st 2008 installers under code are no longer permitted to install 'standard' appliances, they must be a minimum of Band B rated
 
Sorry and meant to add,

for oil boilers, I do not charge any extra for a service of condensing boilers, slightly more work in it, but not a whole lot to charge for!

As for HE gas boilers, charge is usually reduced, as with most HE appliances for many of the services they only require a minimum service as per manufacturers instructions (usually a FGA, clean condensate trap, and check all safety devices) unlike standard appliances need to be stripped and clean on every service (again as per MI)

Tell your heating engineer it's time to leave the dark ages and come into the modern world, the time for chucking expensive fuel away and heating the outside atmosphere is a bygone age! (he most likely things insulation is only needed on space stations too!)
 
DGOBS said:
Sorry and meant to add,

for oil boilers, I do not charge any extra for a service of condensing boilers, slightly more work in it, but not a whole lot to charge for!

As for HE gas boilers, charge is usually reduced, as with most HE appliances for many of the services they only require a minimum service as per manufacturers instructions (usually a FGA, clean condensate trap, and check all safety devices) unlike standard appliances need to be stripped and clean on every service (again as per MI)

Tell your heating engineer it's time to leave the dark ages and come into the modern world, the time for chucking expensive fuel away and heating the outside atmosphere is a bygone age! (he most likely things insulation is only needed on space stations too!)
Click to expand...

DGOBS......I have been recommended BAXI or POTTERTON as the best makes for condesing boilers....would you recommend them?
Also for a 6 bedroom house...approx 2500 sq ft, (gas central heating) what size boiler do i need? My builder is quoting 3,400 Euros for a new Petterton including flushing. Is this reasonable? thanks...
 
Whats the rough cost of replacing a standard gas boiler with a Condensing boiler? Say for a house of 1100 sq ft.
 
3400euro sounds steep, but in saying that I would have to see what the installation requires to judge.........2000 - 2500 is normally the range

Not saying anything against baxi or potterton (same company!)
but if it was my house, my boiler of the minute is Vaillant (and good deal to be had on them as they are just coming back to the irish market after a long absence)

as for sizing, would have to be based on your amount of rads, their size and the types of insulation etc used in your house.
 
I got a Baxi recently, no complaints at all. Used a crowd called www.GasSafe.ie. My dad had used them and we both have only positive things to say about them, think they're based in Tallaght. No personal connection to them.
 
You must log in or register to reply here.
Back
Top