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Fix it or replace it?


Tom Raymond
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I woke up to a cold house this morning, seems something tripped the gas valve on the old boiler. I don't know how long it was off, but the water jacket was below 60 degrees (the T&P gauge was bottomed out), and the house was around 50.

It relit without any problems, but I was already late for work so couldn't stick around and wait for it to come up to temp and run a full cycle. I was back in the area about 3 hours later and it was still running, with the radiator zones at temp and the radiant floor zone almost there. My plumber showed up shortly after I had left again and checked things out.

I bought the house out of forclosure and it had been empty about 4 years. Apparently someone put glycol in the system to winterize it. Plumber say's it is gumming up valves, and likely was automotive antifreeze (but admits that's just a guess). Remember last year I had to replace the zone valves because the gears stripped, so the theory makes sense. Here's his laundry list of repairs:

-T&P gauge is faulty.

-Relief valve is corroded and dripping.

-Packing is shot on several isolation valves.

-Expansion tank is bad.

-Air scoop is corroded.

-Burner and pilot tubes are dirty, despite the fact that I removed and cleaned them in September.

-Thermocouple is questionable.

-And of course the zone valves are still gummed up and the gears will fail again, eventually.

The unit is a Utica 100K btu 80% efficient cast iron boiler. According to the model number it was built in the late 70's, but according to the paperwork I got with the house (including an invoice for the installation) it was installed in the mid 90's.

My plumber says that based on the size of the house (about 1300SF) I can get away with an 80K btu high efficiency boiler with a boiler mate for DHW. I like the fact that I can loose the B vent, as it's not in great shape above the roof line and would need to be reworked when I replace the roof cover, probably this fall. There's also the fact that the new (gas) water heaters are taller than the old units and the 40 gallon short I have barely has enough room for exhaust now, more than an inch taller than I have would require a power vent.

I'm very tempted to limp through the rest of the winter with it and deal with it when I don't need it running, but I hate to put money into something I'm gonna replace in the short term. Any suggestions?

Tom

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I know it will be far cheaper to fix it, I'm questioning the logic of throwing money at a 30+ year old boiler, even if the service life is only half that. How broken does it have to be before it just makes sense to start over? That is what I'm really wrestling with.

Tom

For me, it would have to be pretty damn broken - like holes in the water jacket broken.

I'm *not* a boiler expert. I only see a few each year, but many of them are in the 40-60 year old range and are doing just fine.

Are Utica cast iron boilers really worn out by the 30 year mark?

- Jim Katen, Oregon

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I'd probably be pretty tempted, as you seem to be as well, with total replacement. I'm no boiler expert either, but there are a ton of them here in Richmond and new replacement boilers I run across seem to be pretty nice, and it's impressive how much smaller the new units are than the units they replace. Sounds like you're already zeroing in on several other benefits in your own mind in replacement.

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FWIW, I bet your current boiler, once repaired, will last as long as a new boiler.

It truly is a tough decision. Those old boilers, while less efficient, just never die. I run across old boilers here that are more like Sherman tanks. I especially love the ones with two heavy cast iron doors - one for the firebox that's almost big enough to stick your whole head in there and look around and one to view and clean the heat exchanger.

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My biggest concern is the condition of the burners. I disassembled and cleaned each tube and vacuumed the combustion chamber just a few months ago and it's all full of crap again. There is obviously some serious rust on the iron water jacket.

It's been running fine since I relit it, as long as it stays running I'm thinking I'll tear it down in the spring and do a thorough inspection and cleaning. If the waterjacket is ok, it sounds like I should keep it. All I want is safe and reliable equipment. I don't think that pay back alone is a reasonable reason to replace it, and even with all the rebates and incentives it would be far too long to stomach.

Thanks guys,

Tom

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Don't forget you can get a 30% tax credit up to $1500 on a new 90%+ boiler.

http://www.energystar.gov/index.cfm?c=t ... s.tx_index

Yeah, I knew about that. I am shopping for my roof based on products that are eligable. I'd have to get a hell of a deal on a lifetime roof to ignore the credits, especially with the forcasted increases in asphalt prices this year.

The roof is a project I can't put off any longer, and the primary reason I'm so concerned about what I put into the boiler. I just can't afford to throw good money after bad this year.

Tom

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Most of the servo operated units have spring loaded dampers that fail (hopefully) in the open position. Get one of those.

Three different brands of those had been recalled, the thermally actuated ones are no longer available as far as I can tell. I'll look for a good one and put in the best CO detector I can find.

Better yet, turn the temperature down a couple degrees. Save a penny.

The boiler temp right? With my zone set up and mix of in floor and iron radiators I could probably get away with 140 to 160 boiler temps. It's running 180 now. That makes a lot of sense since I already throttle down the pex loops to around 130, why should I heat the water much hotter than that.

The only thing not mentioned yet is the addition of a thermistor so the damned thing modulates. This is beginning to sound like a lot more fun than installing a new one.

Tom

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Our local utility company pushed those auto dampers really hard in the 80s,when the 90s rolled around they started to realize what a mistake they were! [:-yuck]I replaced a lot of heat exchangers on furnaces that developed cracks from those things sticking shut and overheating furnaces,i either remove them or atleast disable them when i service furnaces.

As far as the boiler goes just because its old doesnt mean its time to replace it!The people i deal with that complain the most about utility bills are the same ones that never service their equipment whether its forced air or a boiler doesnt matter,it needs to be serviced!

Boilers are just like water heaters,i tell people if the flush the trash out of their boiler daily on large commercial boilers and weekly on residential equipment they last a long time.

All that nasty black crud/sludge you see when you drain the water is the same crud that coats/insulates the inside of the pipes and radiators,think of it as boiling mud instead of water [:-weepn]

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Every mid efficiency boiler I've seen that's been built in the last ten years comes from the factory with an automatic draft damper. Weil Mclain, Dunkirk, Slant Fin, Crown... they all have them. Every one that I've inspected worked as designed.

If you're not opposed to having a 6 or 8 inch hole in your house that convects conditioned air 24/7 to the birds on the rain cap then don't install one.

I'd do as Tom suggested: install an auto damper and a CO detector. But I bet you could vent a clean burning boiler into Tom's old basement all winter long with nary a beep a from a CO detector.

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No doubt about that. I lived in a solid stone masonry Quaker Farm home circa 1880. It took an Ashley wood stove, a Copperclad Cook stove, and two kerosene heaters to keep that place comfortable. 7 - 8 cords of wood a years.

The firebox for the cook stove was about the size of a shoe box, so you had to split the wood down pretty small - super high maintenance. I finally converted it to coal. That was anice property, though. THe driveway was almost one mile long and on a clear night, the Milky Way was a stripe that went from horizon to horizon. Miss those days sometimes

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No doubt about that. I lived in a solid stone masonry Quaker Farm home circa 1880.

Wow,

You're one old SOB. What's your secret? Do you change into a liechenthrope at night and feast on human flesh?

OT - OF!!!

M.

A misplaced coma, no doubt. You know what I'm saying. House built circa 1880 me delivered circa 1951. Lol.. but, I am hell bent on living to a minimum of 120! Why not? I'm almost half way there with no aches or pains to date - none!... (knock on wood)... Kinda scary, huh?

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