Last year, a gas company guy told me that my 40+ yo Teledyne Laars boiler was working well, that the newer ones are not as well made, and recommended keeping the Teledyne until it gives out. Unfortunately, we need a new expansion tank, some isolation valves, and could use a new pressure gauge and relief valve. The plumber strongly recommends replacing the boiler while we’re at it. Just wondering if anyone in this situation might try to keep the old boiler. Thanks for any thoughts.
I helped maintain a few of these, I generally just worked on high-efficiency boilers. The expansion tanks, isolation valves and the other valves are easy peasy for a competent plumber. I’d run that thing until the heat exchanger stops working.
They were reliable work horses as far as boilers go.
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NACHI official life expectancy for a boiler is about 40 years. Some go longer, some don’t go quite that long. If it’s at 40+ years, and a qualified HVAC contractor is recommending replacement, I would probably tend to agree with them.
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There are a lot of unknown variables in this equation, but if the boiler itself is operating fine I don’t see a need to replace it. I’ve never worked on that model but the old boilers we used to service would go for decades with regular (proper) maintenance.
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Of course he does… Very few Plumbers OR HVAC Techs have a clue how to repair or even maintain a Boiler!!
Keep the boiler, find a qualified tech!!
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Yes. Running them dry or with air would destroy the heat exchanger. Routine purges are important.
Great time for a reminder that whatever route you take get at least 3, preferably 5 or more quotes on these large investment items. Ask for detailed quotes with specifics broken down.
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And if you get a High Efficiency boiler, make sure it’s modulating and condensing with an external reset. They work beautifully during shoulder seasons. No short cycling because they often modulate down to 25% of their rated capacity and sip fuel.
I highly agree with Mark. Easy repairs items for a qualified boiler technician.
It would be a crime to replace a reliable workhorse unit like that as Mark says.
You can replace it when the heat exchanger gives up the ghost.
PS. Many items on the life expectancy list are a joke.
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We used to replace heat exchangers too. Typically when the whole unit needed replaced, it was due to multiple deferred maintenance issues.
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We did too, but if we ran into a 40YO boiler, getting the parts was not so easy and frankly, at 40 years, it’s had a good run.
Granted, I saw some boilers still working from the 1940s, but they were huge cast iron beasts, probably still running today.
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So, one issue is that the pressure gauge doesn’t work. I was told that it might not be possible to remove the gauge, or for that matter, the pressure relief valve, after so many decades, without breaking the unit. The pressure gauge hasn’t been too much of an issue, but once the whole system is drained, is it possible to safely refill it without a working pressure gauge? Or does the gauge really have to be replaced? Not sure if the pressure relief valve actually has to be replaced either, it’s just very old.
The pressure gauge and “pressure relief valve” could very possibly be replaced in a few minutes without “draining the whole system”. Once again lots of variables. Any photos of the installation may help with more concise answers. You definitely need other opinions/quotes.
Much to think about.
New = Energy savings Operational cost.
40 year old boiler - Energy loss. High operational cost.
The system has to be drained because a valve that I presume was previously been connected to an expansion tank in the ceiling has started to leak, and there are no isolation valves. (The expansion tank was disconnected decades ago and never replaced). A separate issue is whether the gauge and relief valve can be detached without breaking the unit (because the threads may have become stuck together over time…?).
The pressure relief valve should probably be replaced. They don’t last forever. The pressure gauge really doesn’t matter if you have a known, working relief valve.
I understand what they are saying about the pipe. That said, I see a union and other joints and when you’re working with black iron pipe, you can usually get it apart with some heat. Failing that, you cut it off and thread a new union on.
Seriously, anyone who has worked with black pipe won’t have any issue dealing with this. You just need to have the right tools to cut new threads.
I don’t recall whether or not those systems came with a bladder tank or just a steel tank, but do not run it without one, your heat exchanger will blow out pretty quickly. At this time, I wouldn’t run any boiler without a known, working PRV. If they have to plumb in a PRV they can plumb in a T for the gauge ahead of it and leave the original gauge in place.
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Another question. I’m guessing there’s no Low Water Cutoff in this system….? If true, is that something that can be added?
Also, it looks like the leaking valve would be called a pressure reducing valve?
Also, how long do pressure relief valves last? How many times can they go off before they go bad?
And when an old boiler like ours fails, what goes wrong? To me the best argument in favor of replacement is concern about a mid winter failure.
( I don’t know how we’ve gone this long without an expansion tank!)
And any recommendations for what brand/type to replace the boiler with, when the time comes?
Appreciating your answers!
Is there a way to assess the condition of the heat exchanger?
As I stated above…
Keep in mind, when new models of Boilers/Furnaces fail (Never in Summer) 
it is usually because of the Electronics / Control Module! 