Efficiency / Reliability of oil-to-gas conversions?

riguy

Greetings, new guy here because I have a cold house and need to make a repair vs replace decision.

Basics: 11 year old Armstrong Ultra 80 100kBtu forced air, originally oil-fired. Converted to a Carlin EZ gas gun in 2011. Previous owner had those isntalled; we only bought the house recently.

So with winter coming, the Carlin stopped working, red+yellow lockout lights, tech thinks its something in the electrical system (transformer showing only 16V, plus a "hot electrical stuff" smell from the terminal strip). He guesses that repairing the Carlin could be about 1/3 the cost of a new furnace. Seems high to me especially if it's just the transformer, but I can see how if it's more complicated than that, a bunch time swapping that, test this, etc would add up. And we don't know until we start the game, of course.

This tech claimed that the oil-gas conversions have much lower efficiency than what I'd have with a current gas furnace (even a plain old atmospheric vent), and that the oil-gas conversions are more apt to be troublesome, especially when put on a furnace that was relatively 'old'. Plus it would be quieter. A different plumber who was here months ago for a non-heating issue volunteered exactly the same opinions when he walked by the furnace and saw the setup.

So, I'm basically deciding between having a brand new 100k gas furnace put in, or maybe spending about 1/3 that much to repair a 10 year old oil furnace with 3 year old gas gun.

If a new furnace gets me noticably better efficiency, smaller, quieter, and more reliable, I'm interested -- I watched my previous landlord throw silly amounts of money at his ancient oil boiler and I tend to believe it's worth doing things right from a long-term calculation.

But if there's no reason to expect the oil-to-gas setup to be greatly less efficient or likely to break all the time, then I hate the thought of replacing equipment that really isn't all that old.

Any thoughts appreciated! Since I need to make a call quickly -- it gets cold on Friday! -- any info will be very helpful.

Bob Bona_4

You will not regret installing a 90 or 95 percenter gas furnace. For all the reasons you state- smaller, quieter, reliable, and more efficient. And direct vent eliminates chimney issues. Look into variable speed blower units for more comfort.

Or dump more $ into a unit you already hate

BobC

I've had the ez-gas in my Smith G8 boiler for 2 years with no problems and I have not heard of any unusual problems with them. My efficiency was checked last month and it's 84.5%.

If the furnace is in good shape I would get the ez-gas fixed but have it done by someone that understands them. Don't let them just start replacing parts without knowing whats going on.

Bob

BobC

Here is the info on the controller for the ez-gas.

Bob

riguy

I should mention on the efficiency choice, that right now both furnace and gas water heater vent through a masonry chimney, so a HE furnace raises the liner issue. Though the WH is old enough to need replacement, and I guess I go HE on both. That amount of cash all at once starts to bite... ouch.

icesailor

Did that guy tell you that it would cost 1/3 the cost of a new furnace with a straight face?

Is the guy on commission and just a parts changer who doesn't like to change smaller parts? What would he or his boss say if someone like many of us here, waltzed in, replaced the 602000 control, the Transformer, or some other part, and it went running merrily away.

A nice new furnace might be nice if you can afford it. If that is what you want, go for it. But, those EZ-Gas burners are sort of bomb proof. You just have to know how to work on oil or gas burners. Did he figure out how to get it out of lock out? Is an electronic transformer 1/3 of the cost of a new system? Will you pay and save enough over your lifetime to pay for the new install over the cost of repair? I'd be personally embarrassed to say that and be called on it. You have options.

riguy

Appreciate the comments from all.

Icesailor: You are exactly right, and that bad feeling is exactly why I posted here. Even over the phone, their receptionist warned that gas conversions are often not worth fixing. Basically the tech declared it likely we'd have to replace the transformer, controller, terminal strip, and what I assume is an ignition relay, at a cost that hit four figures.

We went with them as a first call due to good online/personal reviews, but I do get the sense their business model is very high volume installs of a small selection of new equipment, and while they might do that well, they didn't seem excited to putter around to get a cranky burner working.

EDIT: Frustrating experience calling techs today from smaller firms that specialize in service. Two oil-burner firms were very familiar with Carlin and had specific ideas about what was wrong over the phone when I described behavior -- but, both said they are indeed oil only, won't work on EZ Gas. Two gas-oriented firms said they didn't feel familiar enough with oil-style gas conversion burners to work on them. So I'm still at square one.

RobG

This is no slight against women (for all I know the receptionist was a man) but if the receptionist is softening you up over the phone for a new furnace it sounds like the majority of the companies training is in sales, not service. Time for a second opinion.

Paul48

riguy......If the "ri" refers to Rhode Island, you need to contact Tim McElwain...he can steer you to someone that will properly service that burner. Put a shout out in the gas section.

riguy

Paul48 - THANKS!! (you're right about the ri)

I did actually come across another guy who knew what I was talking about and is coming to work on it, but if he doesn't pan out for any reason I'll follow up.

Btw, I did a lockout reset of my own, and I've narrowed it down: self-test, blower purge, gas open, and ignition all work fine, from the noise seems like the usual firing. But, the "flame detect" never lights and after 2 seconds it shuts down with the error light. Maybe it's as simple as the flame sensor needs replacing.

icesailor

That sounds like a plan. You might be on to something.

Because you said that it went through all the cycles and lit, with a flame and ran for two seconds, then stopped, get a slam wire with two alligator clips on it, Locate the terminals that say "F-F" on them. Put the clips on the two "-" terminals and start the burner. Nothing should happen. It shouldn't start. Pull one clip off. The burner should immediately start. As soon as you hear the burner start (for that two second trial), put the disconnected clip back on the screw. If the burner continues to run, the flame rod has an issue. Take the clip off and it should stop, quickly. Leave it alone and tell your friend what you did.

I don't like to tell rookies complicated and unsafe practices over the phone or Internet. You went father than most.

I keep telling my oil friends that if they don't start servicing gas equipment, they'll soon be out of a job.

Tim McElwain

When it shuts down what light is flashing? By the way someone here in RI who installs Carlin EZ and have been through my training is the Gas Doctor I will post a phone number when I look it up. The number is 401-942-5000 make sure you specify it is a Carlin EZ GAS!

Spence

There is no reason you shouldn't get a combustion efficiency in the mid to high eighties with your EZ Gas and the right technicians. For example, if your NG is $1.09 per therm and your tech gets your EZ Gas at .82, that 95% furnace would only save $0.17 for every 100,000 BTUH. That's a horrible ROI!

billtwocase

You will be on the right track with Tim

riguy

I know this is a very, very late update, but just for the record I thought I'd post what happened last month.

We did get a guy in who does Carlin oil-gas conversions; he was recommended by one of the oil-only guys and conveniently enough, turned out to be based in my neighborhood.

He quickly determined it was the 60200 control unit, and he had those stocked in his truck, and so popped in a new one for us. Lit up and stayed lit just fine. Whoever did the initial conversion in 2012 had done zero documentation of, well, I'm not sure exactly what -- whatever adjustments/combustion parameters should have been written down. Our service guy checked CO and other things, and we were pleased that he found our burner was actually tuned up pretty well. Total cost about $300.

IceSailor: As I thought back on what first tech did did, you were was exactly right: the tech did not even hold the reset button long enough to get the burner out of lockout! He just held it for maybe 5- 10 sec, it didn't fire of course, and then he declared it dead and a whole new furnace needed. What a joke. So much for the "Big Guys".

Tim: Appreciate the tip, I remember seeing the Gas Doctor website when I was looking for techs. We're ready to replace a gas water heater too (working, just old and we'd rather be proactive). Any RI plumbing/heating firms you'd recommend?

Appreciated all the suggestions here, like I said, you guys did help give me the confidence to listen to my gut feeling that I was being taken for a ride.

John Mills_5

If you replace, get it sized right! Just because there is 100,000 BTU machine there, that doesn't mean it is right. Especially with a conversion burner that could be firing and who knows what.

Also, in efficiency, all need to remember that the figure the tech gives you from his analyzer is NOT the annual efficiency like the AFUE rating is. It is after the furnace or boiler is fully warmed up and at peak performance. It does not look at inefficiency during warmup, doesn't look at heat lost up the flue during cool down or off cycle if the product doesn't have a vent damper. So while a unit could read 84%, annual efficiency could be a whole 'nuther story. A boiler with no vent damper trying to keep the heat in the sections, is probably a long ways from 84%.

riguy

John: Thanks, in fact I was pretty unimpressed at the time that the first tech, or salesman I should say, simply read the BTU rating off the original oil equipment and didn't try to figure out what the conversion burner was set at, let alone do any math at all on what the right answer would be, or even just ask me about how well the heating worked with the current equipment.

Anyway, definitely will not replace anytime soon unless something expensive breaks unexpectedly.