Newbie with some boiler questions.

Grady

Hello all. Need some advice on purchasing a new oil boiler/water. Here's what I have 2300' ranch home, ALL stone (17" walls) 3 people, 1 main bath. Home was built in 1986. Here' the most important info, it's the older style in floor heat/copper, no basement. 8" concrete. (5" pour, then the copper was laid in 3" cement) We live in Northwestern Pa, The home is insulated well. I use roughly 650 gallons of fuel oil a year!



I have now a Burnham, model 14A-T, installed new in 1992, prior to us buying the home. I have a crack in the flue right by the cover plate in the front. I have an older gentleman/ contractor that has worked on the system for a few years. A good guy but not really up on technology.



This Burnham that we have now REALLY has a hard time keeping up. Example: If it's 32 outside and I want the temp up 1 degree, it literally takes an average of 5-6 hrs of constant on/off running of the boiler. When it gets down into the teens, double that time. Once it gets to the desired temp, it'll maintain fairly well. It just takes so long to get the temp up. No, the heating system is not very practical, the builder was a mason, 3 fireplaces.



From the calculations from a couple of sites, my BTU recommendation is 66,000. My question, with everything that I have explained, should I go a little bigger? Also, I've been researching quite a bit and I think the Burnham MPO-IQ is the boiler that I'd like to go with.......fire away

SWEI

That system just calls out for a modulating boiler

is oil your only fuel option? 

Grady

Unfortunately yes

That is my only option.

BobC

Hours to raise one degree

I don't think you can change that.



You have a very high mass heating system and tons of concrete have to heat up BEFORE you see anything in the room, think of it as a giant flywheel. That type of system is best set at a constant temperature, setbacks are not going to work well because of all that mass.



Bob

Jean-David Beyer

BobC is right.

My downstairs is heated by the slab at grade with copper tubes in it. Before I got interested in heating, especially hydronic heating, I got a fancy Honeywell thermostat that let me have four different temperatures each day of the 7-day week. I.e., I could have 28 different temperatures each week.



I thought I would save lots of money by using setback at night, and when I was away.



It turns out that if I change the temperature of the indoor thermostat, it takes 4 to 8 hours for the slab temperature to change significantly, and about 24 hours for the system to stabilize at the new temperature.



I have since gotten a new mod-con boiler with outdoor reset. It is set to provide barely enough heat to make up the heat loss, so the thermostat can call for heat for 18 hours a day sometimes. Thus, even though the boiler can produce about twice as much heat as I need when it is 14 degrees below design temperature, I cannot make it change the temperature of that slab rapidly. I suppose I could change it faster if I had it put steam into the slab, but that would be crazy. I do not ever want to put over 120F in there for very long.



I solved the problem by not using setback at all. If that thermostat quit, I would replace it with the simplest digital thermostat I could get: one with no setback at all. If they even make such a thing. I have it set to do about 1 cycle per hour.

Grady

Constant Temp

Bob, what is the best way to achieve that constant temp?

BobC

Constant temperature

I think the best way to deal with a very high mass system like yours is to select a temperature you are comfortable and set it there, 68-70 or 72 find one that works and leave it there.Make sure you find and fix any drafts that occur when the wind blows. If you have a tight envelope you should be fine.



The Burnham MPQ is a great boiler but I don't know if it's the right one for you. Find an installer you can trust and make sure he knows that comfort is your first concern and ask him what the best boiler would be for YOUR situation at a price point you can live with, you don't want someone installing something that on special at the wholesaler that month. It may cost more than you want but if it's done right it will last a LONG time and you won't get nickel and dimed to death searching for fixes on a botched install.



See if there is anyone listed on "Find a contractor" section of this site.



Bob