I'm looking to convert my home from the 1950's oil boiler i currently have to a natural gas boiler. I've had three different contractors come to my house and offer me five different products in different price ranges. The systems i see mostly recommended have been the W-M and Buderus with one contractor only offering me a Dunkirk boiler. As an add on only one of the three contractors recommended going to an indeirect fired water heater. The other two said just a 40 gallon heater would be plenty with the recovery rate of natural gas vs. my current electric tank.

The units I was offered were a W-M CGI4 and a buderus G124X. Pricing is relatively the same although the contractor offering the buderus was pushing a logomatic control to go with that system which pushes the cost up another 1200 or so. Is there much difference to these systems, is indirect worth the extra 1000 or more for that tank, and also nobody has offered me an ultra high efficiency model. Is my home (~1900 sq. ft) not big enough, not worth the extra cost (not sure what the extra cost would be), or any other reason they would not offer these. Also, the contractor said the logomatic control would make it 20-30% more efficient. How much truth is there to this statement. Thanks in advance and i know i'm asking a lot. This is just a confusing topic for me and the more I read the less I understand.