Ideal Mexico 2 Bed 125 Replacement Intergas

[JackK]

I have an Ideal Mexio 2 BED 125 boiler - Its old and works and is in an outhouse in the garden but my wife wants it changes to something more reliable and new. Its a one pipe system with 3 inch steel pipework !

I have my heart set on a HRE intergas but I dont know the KW to buy - The current boiler prodiduces 50KW at max temp from the manual online so can I get away with a 24 or 30 KW ?

Its a detached 4 bed house with two baths and open vented traditional setup

Also wanted to change the pump to a USP3 pump

Any ideas really appreciated !

 

[CBW]

50kw seems overkill for what you have. I presume you’re sticking with existing setup just a boiler upgrade?

 

[JackK]

Thank you ! I am looking to replace boiler and central heating pump - The grundfos pump is an old one and i thought a sup3 might be a good idea at the time

What I am struggling with is what Kw to choose - Is 24KW enough or should I use a 30Kw - Price difference is tiny

 

[BlueLoo]

Don't run off and buy any pump.
It has to match the setup.

 

[CBW]

I would think 30kw is sufficient, but they can be range rated if too great anyway

 

[JackK]

The pump I have can be seen here - Its a DAB pump green - I thought the USP3 was a direct replacement no?

 

[BlueLoo]

The pump I have can be seen here - Its a DAB pump green - I thought the USP3 was a direct replacement no?

The old one is CS, constant speed.
The ups3 is PP Variable speed, although it can be set to mimic the old CS pumps but this negates the benefits of PP pumps.
You just need to either install the new boiler with this in mind (you might need a small tweek) or use it in CS mode which i bet my last button, the plumber won't have a ****ing clue as to why or what.