Thanks to those who responded to my initial post. From your suggestions I have decided to get a high effiency boiler. In what I have read and what has been suggested I've concluded Munchkin is a good choice of boiler. I have spoken to two well qualified plumbing and heating contractors however they don't agree on the size of the boiler and the size hot water tank and I need some help.
My home is a two story 4 bedroom colonial with 820 square feet on each floor and a portion of the basement is heated for a total of (820 x 2 + 260)= 1900 square feet of heated living area. The walls have R-13 insulation and the attic has R-45. (I don't know whether just this information is sufficient for a calculation. Is there a way I can calculate this somehow to determine the boiler size ?)
The current boiler is the original one - American Standard GPM 6; 38 yrs. old - Input: 165,000 Output: 132,000. The heating capacity to heat the home is fine.
Last month an energy audit gave the boiler a 78.5% efficiency.
My questions are:
1.Which boiler is sufficent ? 80M or 140M ?
(80M Munchkin data shows Input Modulation 27,000 to 80,000 and DOE Heating 25,000 to 74,000)
(140M Munchkin data shows Input Modulation 46,000 to 140,000 and DOE Heating 43,000 to 129,000)
2. What size Superstor hot water tank do I need ? SSU-30 or SSU 45 ?
With 4 bedrooms, one contractor suggests a SuperStor(SSU-30) hot water tank is sufficient. I think I need a SSU-45 with 5 in the family.
Thanks again in advance for your comments. I really appreciate the time and effort of those that respond to make us homeowners more informed.