Information required

Randy Huebert

Good morning. I am attempting to gather information that would enable me to make an informed decision regarding replacing my current residential boiler. I'm not looking for an endorsement of one boiler over another but every quote I've had from contractors indicates that a different boiler would be used. What's a good one, what's one to avoid. Where can I get valid, un-biased information about a boilers reliablilty, efficiency, ranking, warrenty etc. Any information that would point me in the right direction would be appreciated. I am a Canadian resident, but any material generated by the US industry would be relvant. Thank you for considering this request.

Mike T., Swampeast MO

Generalities--but more specific info from you needed

Presuming natural gas a fuel.

1) Standing-pilot, natural draft cast iron. Advantages: simple, low-maintenance, modest cost, long-lived, nearly anyone can service. Disadvantages: Relatively low efficiency that seems to drop off with decreasing supply temperature, flue and heat exchanger condensation can be a definite issue with some systems.

2) High-efficiency cast iron. Advantages: moderate to high cost, curious balance between complexity/simplicity, can wring out additional BTUs from fuel used. Disadvantages: automatic flue dampers in particular are known for short life; may be more prone to condensation damage from low return temperatures; likely to incur more maintenance cost than 1) above. Some European boilers of this type are renowned for their durability, reliability, efficiency and adaptability but do come at a greatly increased initial cost.

3) Copper tube. Advantages: low to moderate cost, generally simple and reasonably efficient. Disadvantages: generally regarded as having a shorter life than cast iron, prone to problems with low-flow rate through the boiler--often caused by "micro-zoning"; condensation is a definite issue with lower temperature systems; water quality can be more critical than with cast iron.

4) Condensing. Advantages: potential for extreme fuel savings greater than implied by "AFUE" numbers or the like, traditional flue is not required, condensation due to low return temperatures is a non-issue. Disadvantages: life expectancy is generally "calculated" as they are quite new, extremely complex, condensate drain required, highest initial cost, qualified service/parts may be difficult to obtain.

Questions for you:

1) What are your heat emission device(s)? Cast iron rads/convectors, baseboard (copper or iron), steel panel rads, embedded radiant, "joist bay" radiant, a mix, etc?

2) How many zones and are any less than 25% or so of the total?

3) Does (or do you plan) the system to use weather-responsive controls?

4) Do you also use the boiler for domestic hot water production?

5) Are you currently satisfied with the level of comfort and control in the system?

6) How is any zoning already accomplished? Valves, pumps, thermostatic radiator valves?