Cost to convert to gas heat?

[RyFitz13]

Hey folks... LOML and I are currently looking into converting our home from oil to gas heat. It's an older home, roughly 2000sq feet, with hot water baseboard heat. We've also got 1 1/2 baths, but may at some point expand the 1/2 to a full. Our current boiler supplies all hot water and heat for the house - we don't have a separate hot water heater, and would like to keep it that way.

Now, I've got a few friends that work in the service department for a local gas company, so I should have the labor piece of the conversion pretty well in hand.

But what should I expect to spend on the actual equipment? So far, I've only been to the Borg - not planning to buy equipment there, just hoping for a ballpark guesstimate. As they only had a single gas boiler there, there just wasn't enough to get a good estimate (and the folks I talked to there were almost completely clueless about the specs of the thing to boot!).

Our Oil boiler was replaced by the previous owner of the home - it's probably only 5-10 years old, and the system is up to code. All I'd be looking to do is a straight swap (if that's even realistic) of one furnace for the other.

Any guesstimates and/or suggestions on what type of equipment I should be looking at? This is definitely something I don't mind spending a few extra bucks on if it'll get me something more efficient and reliable. Thanks in advance!

[maxparot]

Your current boiler could probably be retrofitted with a gas fired burner. That would be the easiest way to go. As need be, you could add in a separate hot water heater and then later replace the boiler with a smaller unit just for heat.

[scorrpio]

I am currently replacing my heating system. I am in Northern NJ.
What I have:
No gas service.
A 40+ year old boiler venting through a masonry chimney, single-zoned for baseboards on both floors, and a separate coil for domestic hot water.
Said domestic water going to an non-functional 20 year old electic water heater - which acts as a storage tank. Boiler output is too high to efficiently work as a tankless DHW, so it is good to have a buffer. Problem is, once heated water is in the heater, no way to reheat it, so if we are away for 2-3 days, we have to waste several gallons of water before heater empties enough that make up hot water from boiler bring the temp up. A mess, really.

Gas company:
PSE&G does not do work inside the house. I need to have everything installed, a gas pipe sleeved out to street near agreed meter location, and have inspector approval - then they come in to hook up gas service. Dunno about your location, but for gas hookup I am paying $65 - the cost of permit to open up the road. Amazing but true - PSE&G will bring in the line from across the street all the way to house for free - that's the benefit of living in a high-credit neghborhood. Hooking gas to homes here is just too profitable to scare off potential customers with install costs.

Plumbing estimates:
Option 1: Install gas piping inside house, replace existing oil boiler with an atmospheric gas boiler (~80-85% AFUE), just connect it to existing pipes. Replace my current water heater with an indirect one. Indirect DHW heater is hooked up like a separate boiler zone - boiler pumps 190-200 degree water through a coil inside heater's tank, transferring heat over. Best system really. A 40-gallon electric heater peak delivery capacity is ~42 gallons in 1st hour, 40-gal gas heater will give you around 55. A 40-gal indirect hooked up to a 105kBTU boiler delivers a whopping 200+ gallons - at boiler's efficiency.

Cost: about $8500. This does NOT include:
1. Chimney inspection, liner repair and certification for fuel switch.
2. Dealing with oil tank. By the law, tank must be removed or formally abandoned.

Option 2, the one I actually want.
Install inside gas piping, remove old boiler/heater. Install a high-efficiency condensing unit (up to 98% AFUE) direct-vented through the masonry chimney. Two 3" PVC pipes are run in the flue - one for venting, another as air intake. Then the chimney itself is sealed. Install same indirect heater as in option 1.

Cost: $14500. In this case, however, I can skip chimney work.

Option to make 2nd floor into a separate zone: $1500 extra. It is so little cause 2nd floor is a single baserboard loop and its supply/return pipes come into basement and tie into current main like 10 feet from the boiler. And this does not include getting a thermostat wire from 2nd floor into the basement.

Option 3, the one I took: DIY. It is allowed here, but of course inspector will be a lot more critical. Gas piping installed not just to boiler, but also to the dryer which I plan to replace with a gas model, and to where I plan to install a gas cooktop during pending kitchen remodel. And installed not under joists as plumber would, but through them (everything to code). Was a b**ch to install. A high-efficiency Weil-McLain Ultra 105 boiler and a Weil McLain Gold Plus 40 indirect heater acquired and installed. 2nd floor zoned separately. All the new piping is hidden between joists. A new interior basement wall constructed to form the utility closet. (Old boiler just stood smack in the middle of basement) Redone all the wiring (which was a mess), but did not add/remove any circuits.

Cost: around $6,000 for all the new equipment and materials. ($4000 for the boiler and heater, the rest is for various valves, pumps, controls, pipes and fittings). Given the above estimates, I'd say total cost of this job done the way I did it would be closer to $20,000.

[gmack5]

Scorpio,

If I had the kind of money you spent on that heating system ($20,000) I'd sit up all nite with it!

[scorrpio]

To give a more direct answer:
1. Swapping an oil burner in your boiler for a gas one is an option for very few boilers. 9 out of 10 your isn't convertible.
2. Flues that have been used for oil burning appliances need to pass a special chimney inspection/certification in order to switch to gas. Expect to shell out $$$ for professional chimney cleaning/relining.
3. Most places require you to do something about the oil tank. It has to be removed or abandoned. Abandoning means calling a special company that will pump out any remaining oil/sludge, clean the tank, and declare it safe to abandon. Costs $$$. Removal costs from about $500 for a tank that's empty and put to the curb by you - to several grand for a buried tank.
4. Higher efficiency condensing boilers like WM Ultra or Peerless Pinnacle have drastically different venting requirements. You need to run two PVC pipes outside - through wall, roof, or existing chimney. Depends from case to case, but it could be a bear to install.
5. A compact high-end condensing boiler also requires much more elaborate piping. Need a primary loop done right with its own circulator and a flow-check and all that. Need to take care of condensate disposal.

[scorrpio]

Scorpio,

If I had the kind of money you spent on that heating system ($20,000) I'd sit up all nite with it!

I spent only $6000 cause I did it myself. I estimate it'd be $20k or more if hired a pro to do it the way I wanted. I got the $16k quotes for what I am sure would be the 'easiest route' type install - pipes hung under joist, vent through nearest wall, etc.

[Hellrazor]

If it was going to cost me $20k to change over, I think I would check into a geothermal system.