How long should a Weil McClain boiler last?

[keegs]

I turned the boiler off during a fuel delivery for about and hour or so the other day and while it was off I replaced the filter. When I restarted it, it wouldn't stay lit. I bled the fuel line a number of times and eventually, after a few hours the problem resolved itself.

The boiled hadn't had a good tune-up in a few years and so I called someone to clean it, change the nozzle etc... After the guy did the work he told me he thought the boiler needed to be replaced. I asked him how he arrived at his assessment and he mentioned something about the access cover and that he couldn't get a brush down between the lobes of the heat exchanger...neither of which sold me on the idea the the boiler needed replacing.

I installed the boiler myself about 20 years ago. It's been cleaned fairly regularly over that time.The combustion chamber liner, the switch, the fuel pump and the igniter have been replaced over the past 5-10 years.

How long should I expect a cast iron Weil McClain boiler to last?

TIA

 

[nybirdman]

20 years is about the usefull life of a boiler.New ones will help off set cost by fuel savings.Right now natural gas is the way to go if you have service.

 

[murphy1244]

Your problem was the thermocoupler, I think he trying to sell you a new one..

 

[Kays Supply]

WM boilers are pretty good ones. Parts are available for them. If the sections aren't leaking, they are repairable. The only boilers I replace are brands that are no longer available and need burners or hoods, or are leaking from a section. However they do need the sheetmetal taken off and the top hood removed so you can do a really good cleaning every now and then. Some are good for several years between this cleaning and others need it more often. It depends on how they are piped and cold the return water is. I am much more experienced in LP and Natural gas that oil.

 

[keegs]

20 years is about the usefull life of a boiler.New ones will help off set cost by fuel savings.Right now natural gas is the way to go if you have service.

I'd love it if gas were available. Diesel is running 3.50 a gallon COD.

 

[tomd999]

Hiya,

First, let me preface this by saying that all my steam boiler experence is with large, high pressure superheated industrial boilers. (think box truck sized and up) That being the case, here goes. If we are talking a standard home iron boiler, I would think 20 to 30 years depending on what the fill and makeup water was like. The more minerals in the water of a boiler, the more potential for scale and mud to build up.

You may want to do a intensive cleaning of both the water and fire sides of the boiler when it gets warm enough to keep the off for a few days. On the water side I would blow the boiler down, pull the hand hole covers, the mud plugs, sight glass and water float then hose it all out. After 20 years there has to be mud built up. On the firebox side, I would look at the refractory and make sure the corrosive high sulfur fuel hasn't eaten away at the walls. (on second thought, your boiler may not be a waterwall design) or refractory brick.

If your having issues keeping the burner running, it's a lot easier to go find an honest oil man and ask him if he has any used burners in good shape. These are around 100 bucks and will make a world of difference.

To digress a little, I have personally fired and run 60 and 70 year old HRT and scotch marine high pressure industrial boilers made by WM and BW. The WM's are good units, however, I prefer to fire a Babcock and Wilcox as I find they are a bit easier to maintain a head with heavy demand

My 15 PSI,

Tom

 

[derek01]

I have seen plenty of boilers over 20 years old still doing fine if the boiler can still be cleaned effectively his assessment of replacing is a try at selling a boiler when it is not needed to convince your self open the sheet metal and clean it your self shine a good light down the flu passages and you will see clear into the combustion chamber you will be able to tell if the boiler it self is OK assuming it is not leaking. MAKE SUre BURNER IS OFF WHEN YOU CLEAN the burner struggling to get oil or air in line has nothing to do with the boiler if is is running with out trouble you are fine.

 

[keegs]

The combustion chamber on this model doesn't have a masonry liner but rather a kind of thick molded fabric. The liner was replaced about five years ago on the recommendation of the guy who had been maintaining the boiler for me who's since gotten out of the business. Before replacing the liner he showed me cracks and areas of seperation that were forming. I think if I recall it, he had to take the burner off and remove the front plate that covers the fire box in order to remove and replace the liner. It was a job I wouldn't have attempted myself.

At the time I was hoping to get another 10-15 years out of it..or until they run a gas line up my street.

 

[keegs]

Well...I've had one thing after another it seems going bad for me with this boiler this heating season.

It's been leaking water, not staying lit and not staying on.

I had a tuneup done about 6 weeks ago and it ran for a while but then the leaks started and now it's not staying on.

This past week I discovered the expantion tank was full of water so I replaced it. That seems to have resolved most of the water leak problems although there's still some water leaking from the 30 PSI relief valve so I'll probably replace it to.

Now it runs for a few minutes and shuts down. I think it may be a bad circulator pump. I can't feel it running and it's cold to the touch. It's either that or maybe a bad thermostat ....I figure.

I've been looking around online for a replacement boiler. This boiler is around 22 years old now and has many of the original parts (including the circulator pump). To have one istalled by a pro is going to cost between $4k - $6k so I'm considering DYI....how bad can it be?

Home Depot has a Slant Fin model LD 30PT for $1750 with a Becket burner included. Not a bad price. Was wondering if any of you have had experience with Slant Fin?

 

[AKwelder]

first lets separate the two items. The fire side and the water side.

The intent of the water side is to transfer heat to the place you need it. If your expansion tank was bad, witch is a common maintenance issue, it would have caused your relief to trip a couple times when thermal expansion raised the pressure in the oiler over the limit. Sadly after a couple trips they never seal as good as new, so replacing it does happen. For some good reading try the site heatinghelp.com

On the boiler is an aqua-stat that takes the input of your thermostats and starts your circulator pump and then uses setting to decide if it needs to ask the boiler to turn on and make more heat. This box has relays and switches in side that do get tired and fail. much cheaper than a boiler switch in winter. If i suspect the aqua-stat i test it by waiting for the boiler to start and tap the side of the aqua-stat with a screw driver. if the vibration kicks off the boiler it may be the problem. in essence the brain is faulty

Circulator pumps go bad, and are replaceable, I like to have a spare myself. but it also usually is controlled by a relay in the aqua-stat.

The fire side does not care if you move heat, all it wants to do is heat the boiler to the set heat and make the aqua-stat say it can shut off

On top of most guns is a box with a reset. this is the primary control and it to has relays and switches in it. check it the same way.

The cadmium cell is the eye inside the gun, if it does not see fire after a few seconds it pops the reset, and if it gets dirty it does not see

the rest of the gun , coil and igniters, call a boiler guy

As to your original post, the guy cleaning the boiler can't get it clean. you can find someone to clean it better, have it taken apart and cleaned, or replace it. but those boilers run forever, with work.