Preparing your Boiler in Spring

As the New England temperatures fade and signs of Spring begin to appear, you can look forward to relying on your boiler less for heating and take advantage of this downtime to thoroughly evaluate your boiler system. Taking care of boiler maintenance, annual inspections, boiler repairs and upgrades will ensure you’ll be ready to start up in the fall.    

Why Spring is the Right Time for Boiler Maintenance

Your Boiler Works Hard in the Winter

It’s been another typical winter in the Northeast, meaning your boiler was probably running almost constantly over the last several months. That wear and tear can create the need for adjustments and tuning within the heating system. Frank I. Rounds can help get your boiler system operating to peak efficiency with a boiler tuning. This might mean a boiler cleaning and replacing gaskets.

Soot Build-Up Is Worse in the Spring

Soot will build up over the winter months inside your boiler. When warmer temperatures arrive, condensation in the boiler mixes with the soot and can start to erode areas of the boiler. The issue gets much worse if it’s left to sit during the hot summer months. When you go to turn your boiler on in the fall, you may find that soot and condensation affected the heat exchanger. Soot removal is an important part of your boiler that helps prevent carbon monoxide poisoning.

Preventative Maintenance Saves You Money

Don’t let small issues with your boiler wait until the Fall. Understanding what components need to be fixed, the cost and parts availability can help you plan and budget appropriately. In a nutshell, timely maintenance will help keep those repair bills low.

Tips for Tuning your Boiler 

Boiler tuning is necessary to maintain efficiency as well as to ensure reliability and safety. Tuning the burner during the spring and again in the fall is recommended because of the dramatic air temperature and density changes that occur during these seasons.

Both steam and hot water boilers need to be tuned regularly. It is important that a boiler is hot before it is tuned. A cold boiler will throw off the actual operating O₂ and CO readings.

Below are the conditions for a natural gas-fired boiler, which is warm, has a load and has a zero-pressure reading on the boiler’s steam gauge.

1. Insert the probe into the stack to monitor stack temperature, O₂ and CO readings.

2. Power the burner switch, and place the burner in the manual mode and at the low-fire point. The burner will now be under the control of the Burner Management System (Programmer), so expect it to go through its sequence of pre-purging and trial for ignition.

3. With a pressurized boiler, check the O₂ analyzer for the O₂ and CO readings. If the CO is above 50-100 parts per million, the burner is running rich, and either the fuel needs to be cut back or the airincreased. A good excess air at low fire is between 5-8% O₂. Also, check themanifold pressure at the burner entrance to make sure it is within theoperating parameters as detailed by the manufacturer to assure proper input.

4. Once low-fire is set, manually increase thefiring rate incrementally while observing the flame and looking for signs ofsoot or instability.

5. At the same time, watch the analyzer at each control point and make cam adjustments (and possibly linkage adjustments) to bring the fuel/air ratio as close to the goal as possible while maintaining safe firing conditions at all times. If the boiler can hold 3% O₂ or 15% excess air from medium to high-fire with no more than 50 PPM of CO, the adjustment tuning is excellent.

6. Take into consideration where the boiler fires most of the time. Set the combustion to the maximum efficiency at that particular rate while maintaining a safe margin of excess air.

7. Arriving at high-fire, and making the adjustmentsalong the way to the cam/linkages or actuators, check the manifold pressureagain to ensure there is full input to the burner as defined by themanufacturer.

8. Manually bring the burner back to low-fire, checking the combustion readings as it descends, and make minor tweaks as needed. During this time, watch the linkage movement on a single-point positioning system to ensure there are no hitches or slippage. Confirming this, switch the control from manual to automatic, allowing the burner to modulate on its own.

9. When the burner has reached its stability pointwith regard to load matching, watch the boiler pressure in relationship to thestack temperature. A well-tuned boiler/burner package will register a stacktemperature between 50-100 degrees above the saturation or water temperature.Anything above this will indicate a dirty boiler or one that has flue gas bypassissues or is badly scaled.

10. Check the safeties, especially the low-water cutoff, the ALWCO and flame scanner.

A boiler that is out of tune increases operating expenses as energy exits through the stack. In addition, soot can build up to the point that the tubes overheat and crack or break from their welds, leading to extensive downtime and excessive repair costs.

Source: Cleaver-Brooks – The Basic 10 for the BoilerTuning