Should I change the boiler?

[hoobsdad]

No doubt this has been asked before - and the answer is probably; how long is a piece of string...but I'm gonna try anyway...

Ok, so reasonable sized terraced property (4000sqft) with 3 bathrooms. Currently has an old Potterton Kingfisher2 CF125 125BTU? boiler that is at least 17yrs old, which up to now has worked ok, but takes a while to heat up water in the hot water tank once empty and is working almost at max. When it gets below freezing the boiler struggles to keep up with heating the house. This boiler is rated G or below by current standards as I understand it

The thermocouple was changed last year, and now seems to have gone again.

Q: Is it worth changing the boiler to go for newer much more efficient condenser types. One that has been recommended is the Worcester Bosch GB162 65KW. What's the life expectancy of a boiler like this, considering that the initial outlay needs to be covered by the savings in gas before it dies....

Many thanks for any thoughts as to alternative boilers or if it's best to keep plodding on with the kingfisher until it dies for good.

 

[lame plumber]

have you got the cash available for an upgrade, if not new thermocouple is a cheaper option. youll save gas on a new one but in regard to heating the house its probably down to poor insulation than the boilers failure to work. best to cure any insulation issues first then consider replacemetn options as no modern boiler will last 17 years, and thats guarenteed

 

[nipper39]

I agree check rads for sludge, if not spend more money on insulation you will save more in long run only change when absolutely necessary.

 

[Ermintrude]

Get BG in ! Only joking. I wouldn't be putting a wb! But insulation, flushing and modern radiators will help a lot, oh and a thermocouple and service !!!

 

[tamz]

I had to convert your 4000sqt to m2 as although i mainly work in old money i can't visualise sqft.
So 370 odd m2. Big rooms :smile:
1st thoughts on reading your post was the 125,000 boiler is probably undersized then i see you have been recommended a 65kw replacement (220,000btu).
Assuming they have sized it correctly after surveying your house, personally I'd be thinking 2 boilers on a header if you have the space. There are a lot of advantages in this set up over a single bigger boiler and no disadvantages.
Life expectancy of any new boiler won't be close to your kingfisher but they do their job well and will pay for itself in lower bills.

 

[hoobsdad]

thanks guys and girls, all very useful information. I think the biggest issue is insulation as you all say. I think I should review what insulation is in the loft...It all looks manky and probably not doing much. And yes, like the idea of a £7 thermocouple rather than a £2K boiler!

Tamz - I'm interested to hear about two boilers though. Would that not use more gas over all? I take it this will re-heat the water in my hot water tank quicker? There is a 100 litre? hot water tank (its about 4ft high) which gets abused all at once in the mornings. Would having two boilers help sort that problem? Or is there a cleverer way of making sure there is enough hot water (I know...people - read teenagers - could use less...but that's never going to happen) - at times of high demand, such as a second tank which only gets heated in the morning?

the bottom line is that I am trying to reduce my costs...aren't we all...I have a feeling that only by moving into an unheated tent and getting rid of my family will this happen...

thanks again for the help.

 

[oz-plumber]

Dear Friend,

I get the feeling that it will not be your choice to move into a unheated tent.
It will be your family's choice for you - unless of course you get this problem solved.
If you wish to be removed from your home, by your family, after the problem has been resolved then all advice given - will be in good faith for your family.

As Tamz states, it would be better to have two smaller boilers installed for a house of that size.
With some careful thought, the system could be set-up to have both boilers working when necessary and have one shut down when the temperature in the house / heating water is able to be maintained by one boiler.
The boiler that is designated to be shut down could be set up to be the primary heat for the Hot Water cylinder.
Meaning that even when the heating is required , the secondary heating boiler - primary hot water boiler could be used to heat the hot water without any great effect on the heating system.
In summer one boiler will be used more than the other and vice versa in winter.

Hope this makes sense

Oz Plumber