Replacing 30 year old Oil Boiler

jrunks1221

Looking to get some advice one replacing an old oil fire boiler. I live in an old farmhouse in very northern NY. The house is well insulated for its age, having an energy audit done and sealed fairly well. I initially wanted to get a combi unit but one of the two companies techs that came to look at the setup said that they do not work well for standard baseboard heaters and only really work well for radiant floor setups. Is this true? Below are the two main items on the quote, I like to do research of my own on major items but could not find anything.

Installation of a Cast Iron LP-Gas Chimney Vent Boiler and a 50 gallon Purepro Stainless Steel indirect domestic water heater
Recommended boiler: PurePro Advantage series 117K BTU

EBEBRATT-Ed

Mod cons and combi's are fine but you need someone who knows how to service them.

Standard boilers need service too but are more forgiving.

You can use combi's and mod cons for baseboard heaters but the efficiency will change.

Lets say a standard CI boiler like you were quoted is 84% efficiency.

A mod con or combi used for a snow melt system or radiant floor heat (low temp system) will be say 95%

a mod con or combi used on baseboard will be around 89%

This is because condensing boiler's can't condense at higher boiler water temps. They still modulate and save fuel though.

But we always say the installer is more important than the boiler.

Combis are more $$$ , and don't last as long and need more service (specialized service)

CI boilers are less expensive, easier to find service and last longer but lower efficiency.

hot_rod

If the energy audit includes a heat load calculation that would give you some useful info.

Next step is to measure how many feet of fin tube

Times 550 btu/ ft. See how it matches the heatload number

In some cases the boiler can run much lower than 180 f.. The lower the operating temperature the more efficient the boiler will operate

With outdoor reset control , much of the season a mod con will modulate down to a lower firing rate. This saves fuel $$ and increases comfort with less boiler cycles.

Plenty of homeowners learn how to service and clean their mid con boilers.

mattmia2

let's clarify that you have fin tube baseboard emitters?

Steamhead

@jrunks1221 , what boiler do you have now?