I'm Angus and looking for a new boiler recommendation please.

[Gusty1]

I'd like a new system boiler to replace my old Pottterton 120L which is a 35KW boiler. When it worked it was a good boiler but I noted it cycled on/off most of the time, I assume because it heated things up quickly and then switched off whilst all that heat dissipated around 14 radiators. 8 rooms, 4 bathrooms. (probably half the radiators go off quite quickly when they get to (or are already at) a 1 setting as we only heat the main rooms). Have a large hot water cylinder which enables two power showers or a large bath now and again. No intent to move away from a system setup. Boiler is in a kitchen cupboard, on an outside wall in a 4th (of 5) floor flat.
I am drawn to Worcester Bosch due to it coming highly recommended but would love to know what would be the optimal solution for good trouble free operation for the next decade or so.

 

[ShaunCorbs]

Probably around 14kw but best to get a Heatloss done or at least measure up the output of the rads if they heat up the rooms ok

 

[Chuck]

A problem with heat-loss calculations for flats is that the heat required depends on whether the neighbouring flats are occupied and heated, so that's a factor that needs to be considered.

Keep in mind that whether a boiler cycles or not depends on the minimum output not the maximum output.

IME, Worcester Bosch still have a very good service network, at least in my part of the world, but the quality of their boilers has dropped in the last few years as they've starting using more plastic-components packed in more-tightly. These days, I'd give serious consideration to Vaillant as an alternative.

If you use the 'Search' facility for this forum (top right on this page) you'll find several recent threads discussing the pros and cons of various makes and models.

The quality of the installation matters. My advice is to start by finding a good installer who will do the heat-loss calculation and can explain the pros a and cons of different boiler models and types of control.