Old Oil Furnace Efficiency Question

[Vito Cavallo]

I have an old 1920's house with a big old rectangle oil furnace. The system is steam heat. The furnace is about 4 feet tall, 3 feet wide and 6 feet long. House is 2 floors (plus finished attic), 1400 sqft.

When my furnace turns on, it takes about 1 1/2 hours before I hear steam hissing through my radiators and feel heat. I have 9 radiators in my house. House is uninsulated, but will be soon.

Is this too long of a time for a furnace to burn before I can feel heat? What is a normal range before I should get heat? I live in Boston and went through 700 gallons of oil last winter ( very cold last year).

I know the system is old and I will weigh the options of furnace replacement vs. oil price when I get some feedback.

Thank you.

[Vito Cavallo]

I have an old 1920's house with a big old rectangle oil furnace. The system is steam heat. The furnace is about 4 feet tall, 3 feet wide and 6 feet long. House is 2 floors (plus finished attic), 1400 sqft.

When my furnace turns on, it takes about 1 1/2 hours before I hear steam hissing through my radiators and feel heat. I have 9 radiators in my house. House is uninsulated, but will be soon.

Is this too long of a time for a furnace to burn before I can feel heat? What is a normal range before I should get heat? I live in Boston and went through 700 gallons of oil last winter ( very cold last year).

I know the system is old and I will weigh the options of furnace replacement vs. oil price when I get some feedback.

Thank you.

[Zypher]

Vito;

You have a 'boiler' which heats water, which runs through baseboard heaters or radiators. Each radiator should have a thermostat setting for that room. I'd call your friendly neighborhood HVAC person, (and be sure to ask if he's a licensed boiler mechanic). He can inspect and adjust your oil fired boiler to its best running effiency.

[Speedy Jim]

700 Gal in NE for an un-insulated 1920 house is probably normal. Let's say (for argument) that you could improve the boiler's (not furnace) efficiency by 10%. You would save 70 Gal/yr on a capital cost of ~4000. Do the math.

Those may not be real numbers, but you get the idea. Put a couple of Grand into some real insulation first.

YMMV

The boiler will start steaming faster if its water temp is maintained at 180F when idle. It may already have a control to do that or one can be added.

Jim

[Edwin Pawlowski]

You don't have a furnace, you have a boiler. 700 gallons is not bad for an average size house in your area. I'm 70 miles from you and burn that much in a well insulated 2000 sq. ft. house.

Yes, 90 minutes is much too long to hear steam. There could be a couple of problems. First, the burner must be firing at capacity. No restrictions on the oil flow, no clogs in the flue.

Next is the water level. Steam boilers must have some head space at the top of the heating drum for the steam. It should NOT be over filled and have water in the pipes. Overfilling can occur if the feed vale has a slight leak by and over the summer, it seeped in and filled the system. That would make the boiler heat all the water and bubbles of steam would have to work there way to the top to work properly. Is there a sight glass to show water level? If you see nothing, it is either empty or overfilled. Either condition is bad.

If you have no clue what I'm talking about, call a pro. You don't want to take chances with a steam boiler. They are perfectly save, provide excellent heat, but must be maintained.

[Clark Griswold]

I had the same heating system (one pipe steam) and the same age dwelling. The steam boiler was installed around 1940 as a replacement for a gas/coal system. Dumped it last year for a new boiler and fhw baseboard.

An hour and a half is a tad to excessive. It should only take less than fifteen minutes for the air vents to start hissing.

It could be any number of a hundred or so things that could be wrong - pipe insulation, air vents, main vent, dirty combustion chamber, etc.

is full of valuable info. You could post your question on "The Wall".

One thing you should think about doing is have a *steam* heating pro clean and check out the system.

[m Ransley]

As Clark Griswald said alot of things to consider. Inulate now and if you replace the unit size it with future insulation factored in the calculation. Is boiler and piping insulated, are vents old and hiss. You don`t want this as vap[or escapes requiring makeup water. Does boiler require makup water every cycle? , Not good. Is heat even. Steam needs attention for set up and maintenance and can throw off efficiency. You need a good tech and need to learn your system. 1 1/2 hrs is to long to generate steam.