In oil heat service there are some basic rules that can carry over from and into the rest of your life. If you’ve ever been to one of my seminars, you might remember my 12 Laws of Service. You might also remember Law No. 2 is assume nothing, which is a good attitude to have when entering a customer’s home since my first law is listen to the customer.
This article has to do with Law No. 2 and also Law No. 12, which states, ‘Eyes and people can lie, test equipment can’t.” Although test equipment can’t lie, it can age ‘ leading to inaccurate readings ‘ and also just fail, which is the point of this article.
Recently, I had a customer call me and say that he just couldn’t get a hot water (hydronic) system to purge out unless he increased the system pressure. If he did that, he had the relief valve blowing off when the boiler reached limit. Well, you know there are a few things at work here and lots of possibilities. But remember, it’s the simple things that can cause more anxiety and grief than anything.
System pressure is one part of it, but we also have expansion of the water and the devices controlling that expansion, the charge on the expansion device, the quality and condition of the pressure reducing and relief valves and a bunch of other things, but it turned out that it was simpler than that. Have you figured it out? If you said a bad theraltimeter, also known as a tridicator or just a good ole boiler gauge, you got it. He spent a lot of time on this job and a few return trips too, costing both the customer and himself money. Although he trusted the gauge on the job, he assumed it was good’wrong assumption.
When working on a problem like this, very quickly take out a test gauge and verify that the gauge on the job is working and has some degree of accuracy. In Figure 1, we have a test gauge that can easily be applied to any application for the testing of boiler pressures, system pressures and for testing domestic hot water heaters too. It’s not only essential for putting you at the starting point in analyzing hydronic system problems, but it’s so important it shows up in two of our books for troubleshooting domestic hot water problems, Hydronic Systems and The Hot Water Handbook.
Every serviceman must have the tools, gauges and instruments to successfully complete the service call. However, he must also have the knowledge to see beyond what’s apparent and an open mind to what can’t be seen, which is where trusting test equipment becomes so important.
By the way, many complain about these gauges not holding up in our line of work, which includes a lot of cold weather conditions. Again, like so many things there are tricks to making things go easier. When using the gauge in cold weather, remember that you just exposed it to water and that water will freeze. When the water freezes, the movement of the gauge is fatally damaged. To prevent this from happening you need two things. First, pick up a hose plug, which can be purchased just about anywhere including most hardware stores. You’ll also need a bottle of witch hazel or isopropyl alcohol, which you can buy in any drugstore. If you have any left over non-toxic anti-freeze from a job, that works well too. When you get done with the gauge in the winter time, or anytime, pour a little alcohol into the gauge and adapter and insert the hose plug. The alcohol will prevent freezing, and you’ll be amazed at how long your gauge will last.
The next part of this article has to do with an oil technician’s most important gauges, pressure and vacuum. Rather than get into a long sermon, I would rather tell you why you need a liquid-filled gauge (Figure 2) from the perspective of why an engineer will buy them. Here’s a Q & A from a prestigious engineering journal with my comments afterwards:
Q. What are the advantages of using a liquid filled gauge in testing?
A. Liquid-filled pressure gauges provide a number of advantages:
1.The liquid absorbs vibration and pressure spikes leading to more accurate readings. It can also show faulty conditions within a pump.
2. The dampening action of the liquid enables the tester to take a reading during conditions of rapid dynamic loading and vibration. Great for cut-off tests, whether vacuum or pressure.
3. The liquid lubricates all moving elements, dramatically reducing wear in the movement. That means your gauge lasts longer.
4. Because most liquid-filled gauges are filled with non-aqueous liquid and hermetically sealed, they perform in corrosive environments and are immune to moisture penetration and icing. This is important when you work under the climatic conditions we do.
So, if you haven’t made the jump to liquid-filled gauges, I suggest you do and work easier, not harder. All of the gauges in this article are readily available and can even be purchased on my Web site.
George Lanthier is the owner of Firedragon Enterprises, a teaching, publishing and consulting firm. He can be reached at Firedragon Academy, 608 Moose Hill Rd., Leicester, MA His Web site is www.FiredragonEnt.com and his phone number is 508-421-3490.