Vaillant system boiler

Jul 19, 2005 4 Replies

I'm having an Ecomax (heating only, keeping old hot water tank) put into my smallish three bed terrace house in Oxford, and just wanted to check a few things after getting conflicting info from two installers.


The one my installer is choosing is an 18kw one - is this too big? The other guy says I should have a 13kw one, but the first one says the



18kw is fine, and can be set at the kilowattage you choose. Obviously I'd like the system to run as efficiently as possible as it is certainly not cheap! Any tips related to this? Also, the first guy is intending to remove the make up tank from the loft, and the second says this isn't necessary if I have the 18kw boiler.


Thanks for any help!



Well my house is a four bed and i've got a 28kw system boiler which does the job nicely. When guaging the power output for your property for a system boiler, how many bathrooms and showers you have also plays a heavy part.

The boiler you get should be modulating, so having a boiler that is too powerfull isn't a problem.

I'm sure the usual cronies will go more indepth.

The boiler will modulate down so this is not likely to cause any problems. If the HW cylinder is old replacing it with a fast recovery one that can soak up all the heat the boiler can provide will be worth doing if you ever are running baths in quick succession.

It also reduces fuel consumption too.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required