"plastic baggie" isn't a stock part on a domestic boiler

December 19, 2023 7:25 PM

My elderly mother-in-law got a new heating boiler a couple of years ago. It has never been reliable, with the repair folks come in roughly once a month as it's still in warranty. I don't know much about domestic heating systems, but when I looked at the boiler today, there's a baggie wrapped around the expansion tank that's badly stained with rusty water and looks like it regularly gets a good quantity of leakage. It shouldn't do that, right? But I don't know who or how to ask

We're with my mother-in-law (87) near Kansas City, MO for a few days. We live in a different country. There is a highly technical family member living in the same state, but he's not getting involved for some reason.

The house is very old: built for the guy who prosecuted Jesse James. Its old heating system died a few years ago, and my m-i-l got a new Lochinvar system put in in 2021. She used a local contractor, and the device and labour have 5 years warranty.

The boiler keeps going out, however, and the folks the service company sends seem to be different people every time. I have a faint suspicion that they made an installation/specification error when they put the thing in, and might be trying to fob my (very) non-technical m-i-l off until the warranty runs out.

I could call the repair company in, but the boiler's working at the moment. I'm pretty sure they're not going to admit any error on their part. The leaky plastic bag thingy isn't a hopeful sign. I sat through a startup/ignition cycle and it made all the right sounds (gas valve click, hiss for a couple of seconds, igniter glow, ignition whomp, boiler stays rumbling for a while, gas valve clicks closed, flame goes off).

A further confusion is that the company installed a rather nice mini-split heat pump around the same time, which my m-i-l only really knew was an air conditioner. They also replaced the gas water heater with an electric one. She hasn't had any guidance on running the new system, and is keeping electric oil-filled radiators around the house running to make sure the house doesn't freeze in winter. This response may not be entirely rational on her part (she has friends and neighbours nearby she could stay with if it got really cold) but is understandable if she doesn't understand how the heating's supposed to work. There's no documentation, and as far as I can see, the old single-set thermostat is the only controller.

posted by scruss to Home & Garden (6 answers total)

Not a professional just have spent way too much time learning about boilers. I think expansion tank leaks are probably fine, or at least not critical. What are the reasons for the boiler going out in the past? if you get the reasons or the codes, that will tell you a lot more.

Also worth calling in another heating person to take a look. Sure you'll pay for it, but they'll be more impartial.
posted by so fucking future at 7:52 PM on December 19, 2023

Expansion tank leaks aren't critical, at first. Then it's new years day and the expansion tank is spraying water all over your boiler room and you don't even know who to call but it actually doesn't matter because they're all closed. Ask me how I know.

But the interesting thing is that plumbers do expansion tank replacements (ie, you don't have to call the boiler guys, my plumber definitely knew how to replace it) and your leaky expansion tank may well have nothing to do with your other boiler issues. Expansion tanks can be finicky, they don't last super long in general and sometimes you just get a dud.

Residential boilers are such a huge pain. So much can go wrong, and at least where I live they aren't common so there's only a few companies we can call and they all charge a lot. I'd consider just calling an entirely new heating company to get their opinion, but if it's working now they might not be super helpful (but they'll definitely charge you for the visit anyway!) so up to you whether you want to go that route. But I'd definitely call around plumbers to try and get a new expansion tank.
posted by potrzebie at 9:51 PM on December 19, 2023

From a commercial HVAC perspective, but applicable here. First an expansion tank is pretty critical, and needs to be addressed. It shouldn’t be leaking, and if it is, this soon after installation, it’s a problem. And when you say the boiler itself is going out, do you mean the boiler stops firing? If it’s a condensing boiler (and I’m a commercial guy, not so much residential, and although the skill set translates, the equipment is different), then a lot of Lochinvars in my line of work have an issue with gas pressure drop. If the gas pressure drops more than 2” water column (when firing on natural gas) when the boiler fires, it’ll cause the boiler to burn too lean, shudder and make loud noises, and ultimately go out. This is an issue on modulating boilers mostly, and tends to happen when it is very cold outside and lots of people are using gas. There’s not enough information here to even begin to speculate on a diagnosis, but in terms of what you should do, absolutely call a different company. See if you can get in touch with Lochinvar and have them recommend dealers in your area, and use a third party who has an established relationship with Lochinvar; like another poster said, a third party won’t have as much skin in the game, and is more likely to be honest. What it sounds like needs to happen is a Lochinvar rep come and observe. That that hasn’t happened yet after a few visits is surprising and sus. Typically when a system believed to be installed correctly keeps having an issue, the installer will get the manufacturer involved to figure out how to be done with the issue, for a couple reasons, as warranty work isn’t profitable, and also, manufacturers will typically have a protocol they follow, and before too long, they’ll want to be involved if they’re going to keep paying warranties. And hopefully if the next company finds the issue and it does turn out to be install related, you can fix it and explore chargeback or other options against the original company to make you whole. All that won’t be fun, will possibly be fruitless, and will be a huge headache.

I briefly worked for a residential company, and they got bought out by private equity. What led me to leaving that job was finding that the company installed a system wrong (they ran too much exhaust piping, with the wrong kinds of fittings) which I found while diagnosing a failing exhaust motor. When I mentioned that the exhaust piping was wrong and needed to be repiped, the company told me to ignore the issue as it would make the company look bad and not be chargeable if we fixed it. I cleaned out my van that night, made a very satisfying phone call, and went back to commercial. Tons of residential companies are being bought out by vulture capital, and the craft of this trade is being sidelined in favor of profits. Not saying the company you hired is necessarily, but it happens and is a plague on the trade, and shady companies will absolutely lie about what they did wrong to cover their own ass. Find a reputable, locally owned, uninvolved Lochinvar dealer to bring in, and hopefully get to the bottom of the issue.
posted by HVACDC_Bag at 3:22 AM on December 20, 2023 [12 favorites]

I don't have anything useful to say on the topic of boilers, but wanted to comment that I used to live just up the street from your mother-in-law, and that I do not envy you/her trying to care for that house. It's beautiful but feels like it'd be a lot of work.
posted by jferg at 4:51 AM on December 20, 2023 [2 favorites]

You might try asking on the heating help forum. Lots of HVAC pros are active there and the focus is almost 100% on steam and hot water boilers there. They will want pictures of the installation. There are definitely some MAGAhats there, but the technical knowledge is good and many of the regulars are decent folks.
posted by Larry David Syndrome at 5:09 AM on December 20, 2023 [4 favorites]

Calling another hvac company to do a “service” would identify any visible issues with the system. Should cost less than $100.
posted by Geckwoistmeinauto at 4:53 PM on December 21, 2023