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This was originally written on January 26, 2004 when a heavy snowfall shut our company down for the day. I updated it October 30, 2004. Enjoy. - Frank “Steamhead” Wilsey I did a job last week that really made me think.
The lady called us in desperation- the oil burner kept tripping the circuit breaker and no one would touch it. "It's too old to work on," they said. "”The only thing we can do is replace the entire boiler." And she almost had a heart attack when she heard what they wanted for doing so.
So I cleaned the boiler’s flueways, set up the Beckett to burn 1.00 GPH (about 140,000 BTUH input) and started it up. I quickly noticed the stack temperature soaring- it stabilized at 835 degrees. The old stack relay cut off the ignition after about seven seconds of operation! The system heated up nicely, but as it did I noticed the pressure soaring along with the stack temperature. The old Mueller safety valve was only dripping- it was probably rusted up from the old steel pipe it was installed with. I drained enough water from the system to fill one radiator with air to allow for expansion, which kept the pressure under control, and arranged to return and install a new dual valve and add an expansion tank and backflow preventer. The lady was thrilled to have the heat on, and kept an eye on the pressure gauge until I returned.
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The system in question is a small gravity hot-water job in a 2-story rowhouse, with 340 square feet of radiation. The original boiler, a 1927-vintage National round 4-section, is still in service. As originally installed, it had an early-model Mueller dual feed/safety valve and no expansion tank. This setup was also still in service. Sometime in the 1950s or late 1940s, a Quiet-Heat conversion oil burner was installed.
I went there with a good used Beckett in the truck that we'd kept when we replaced the boiler it had been installed in. We have a habit of keeping these around for just such situations as this, and I was glad I had it that day. I removed the Quiet-Heat and prepared to install the Beckett. I looked at the nozzle in the Quiet-Heat- 1.25 GPH! Remember, this system has 340 square feet of radiation, which translates to a Net rating of 51,000 BTUH at a boiler temperature of 180 degrees. A 1.25 nozzle will burn at an input rate of about 175,000 BTUH- over twice what the system's Net rating should be.| Dan Holohan - [Intro] | [Email] | [Website] |
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