15 years, 2 cracked blocks, 1 leaky indirect water heater coil

saikosis

We bought our house in 2011. It had an oil-fired steam boiler of unknown age.

In January 2012, I noticed that I was adding a ton of makeup water. The block was cracked. I got a new one under warranty.

In December 2013, we switched to natural gas and got a new Weil-McLain boiler and an HTP indirect water heater. The contractor also fixed a lot of issues with the previous install (https://forum.heatinghelp.com/discussion/147386/whats-wrong-with-these-pictures).

In October 2025, the coil in the water heater sprung a leak and flooded the boiler and nearby piping (https://forum.heatinghelp.com/discussion/202257/dirty-hot-water-boiler-overfilled-related). Replaced under warranty.

Just a few days ago, the annual boiler maintenance revealed a cracked block again. Warranty expired three years ago.

What's going on? Is my town's water supply mixed with battery acid or something? What's the expected lifespan of a steam block?

Once the new boiler goes in, what should I do differently? Periodic testing and treatment of the boiler water? Whole-house water treatment?

mattmia2

how much makeup water are you adding? leaky systems that are causing a lot of makeup water to be added usually corrodes boilers. a typical residential system that is not leaking should lose less than a gallon a month.

Big Ed_4

No ,its not the water….

saikosis

There's an automatic feeder with a meter on the current boiler. Contractors have been inconsistent about resetting it during maintenance, so I don't know the total volume of makeup water. Whenever I've looked at the meter, it's always been low, like under 10 or 20 gallons. (Edit: by "10 or 20 gallons," I don't mean that it's adding that much each year. I mean that that's what the meter shows year after year until a contractor happened to reset it. Then it would creep up again to 10 or 20 over a couple years until someone else reset it.)

There's a manual bypass, so who knows how much new water has been added as part of maintenance.

I've flushed the boiler myself once. In December 2020, my regular contractor dumped a bunch of chemicals in it and then said he'd come back later to finish. This was the first time any additives were used, as far as I know. A first floor radiator puked purple brown water soon after he left, and then a second floor radiator did the same. I drained and refilled until the sight glass was showing clear water again, not the purple brown stuff. The guy never came back. No idea what damage this did, but the system was never quite the same after.

When the water heater leaked last year, it pushed a ton of water into the boiler and even up into the pipes. Not enough to come out the radiators, but it took many five gallons buckets to drain it back to normal level. While waiting for the replacement, I kept the bad one isolated as much as I could to keep fresh water out of the boiler, but I had to turn it on for showers and washing dishes. I'd guess I drained over 100 gallons between when I did big initial drain after first noticing the problem and then a bunch of smaller drains up kept it stable while waiting for the replacement. And who knows how much it added to the boiler before it got bad enough to be obvious.

Steamhead

@saikosis , where are you located? We might know someone who can help…………………

saikosis

I'm in Southeastern Massachusetts.

Steamhead

Try New England Steam Works:

https://heatinghelp.com/find-a-contractor/detail/new-england-steamworks/

EBEBRATT-Ed

Or @Charlie from wmass but it is probably a hike for him.

EBEBRATT-Ed

@saikosis

I would really search for the right contractor. no reason to keep changing boiler although S Eastern MA and RI seem to have water that eats boilers. Might consider a Burnham Steam MAx for gas fired

109A_5

It may just be bad luck.

Additionally was the block actually cracked or did it rot out ? Kind of makes a difference to me.

As far as water consumption, I'd personally keep better track of the readings, although by your description the normal use consumption seems low.