We are going to replace a 1940's steam boiler (coal converted to oil fired) with a new unit. There are some questions that we have for this install that I would like some experienced advice for. Survey Data: * Two pipe low pressure system with a float type condensate return pump. * Total Square Foot EDR = 650 * Total calculated building heat loss = 160,000 BTU * The building is single story and has about 125 feet of insulated 2 inch horizontal mains. * The existing boiler has a water capacity of 8 gallons between the N.W.L. and the LWCO. *The existing boiler firing rate is 2 GPH * On a cold start the existing boiler runs for 12 Minutes (starting from the time the header gets hot) and steams off 4 gallons of water before the condensation pump will turn on to refill the boiler. Question 1. Due to the length of the mains what is a reasonable pick up factor to apply to this system....... is 1.5 sufficient? I calculate that with a pick up factor of 1.5 the replacement system should have a DOE Capacity of at least 234,000 BTU... Does this sound correct? Question 2. Of the currently manufactured boilers that I have researched, none have a water capacity that matches that of the existing boiler. I understand that I will need to install a "reserve tank" to supply the new steam boiler with enough water to produce enough steam to fill the radiators and the pipes of the system. I calculate that I will need about 2.5 Gallons of "reserve water"... What is typically used in these situations as a reserve tank? I have seen that some have used plain compression tanks, but a compression tank can be expensive, and I have not seen any horizontal CT tanks with both top and bottom fittings to connect to the system..... Does a pre-manufactured reserve tank exist? Could I weld one from a length of 1/4 steel box beam and cover the ends with plates?..... Would that pass code?? IMPORTANT... Because the new boilers water capacity will be increased with "reserve water", Is it necessary to oversize the boiler to allow for that increased capacity, and if so by how much? Question 3. If I went with a tankless coil option on the new boiler, how much do I have to over size it to compensate for that heat loss? Question 4. I really like the "Peerless ECT" but it is expensive. I have been told that the Crowns are good, and they are reasonably priced, but their largest residential boiler only has a DOE of 235.000BTU, and I don't think it will be big enough for this install. Who else makes a good, reasonably priced boiler that is sized large enough to replace the existing boiler for this install?

I have noticed that a sorta humming noise has been coming from my radiators. In the basement, it seems the noise can be isolated to the Motor next to the boiler system. Although through the years (and the help of this forum) I have learned to maintain the boiler better (adjusting pressure. etc)...I have never maintained this motor. Could it need oil? Please advise. Thank you kindly.