- Home
- For the homeowner
- Safety
- Definitions
- Gas furnace
- Some error codes for gas furnaces
- Service sheet for the gas furnace
- gas furnace design
- The gas heat exchanger
- Dangerous conditions in gas furnaces
- Annual service of the gas furnace
- Repair procedures for gas furnaces
- Gas fireplace millivolt systems
- Oil furnace
- Setting gas input
- Quick tips for troubleshooting furnaces
- Troubleshoot
- Operation and troubleshoot furnace by manufacturer
- HVAC war stories blog
- Annual service of an oil furnace
- Oil furnace design
- Oil furnace troubleshoot
- Repair procedures for oil furnaces
- Gas code training
- Piping and connections
- FAG w pilot no fire
- Combustion analysis
- Electric furnace
- Air conditioner
- Refrigeration
- Heat Pump
- Boiler
- Ductwork design and troubleshoot
- Thermostats
- Diagnostic problems
- Tools
- Electric test meters
- Electrical diagram training
- Electrical symbols
- Single and 3 phase power systems
- Electric wiring solutions
- Transformer design and troubleshoot
- Electronic air cleaner
- Blowers and fans design & troubleshoot
- Humidity and humidifiers
- Furnace, Air Conditioner and part manuals
- Electric motors
- Run Capacitors
- Start capacitors
- Troubleshooting the capacitor
- Gas furnace short cycling
Increasing the efficiency of the older oil furnace
The best way to get high efficiency from an oil furnace is to buy a newer furnace. That is not always possible.
This method assumes you have a flame retention head burner. If you have an earlier type of burner, you must change out the burner to get any sort of efficiency out of the furnace.
So for those that need it, here is a method to perhaps get a little more efficiency out of an older one. I does require the use of combustion analysis instruments to get the best you can without sooting the heat exchanger.
You can't get good heat transfer with a sooted heat exchanger. Any good you may do by increasing burner efficiency is lost if the heat cannot transfer to the air passing over it.
The video below covers cleaning of the heat exchanger. The method used is not the best, as a very powerful vacuum is necessary to do a good job. A commercial vacuum job is the best.
This method assumes you have a flame retention head burner. If you have an earlier type of burner, you must change out the burner to get any sort of efficiency out of the furnace.
So for those that need it, here is a method to perhaps get a little more efficiency out of an older one. I does require the use of combustion analysis instruments to get the best you can without sooting the heat exchanger.
You can't get good heat transfer with a sooted heat exchanger. Any good you may do by increasing burner efficiency is lost if the heat cannot transfer to the air passing over it.
The video below covers cleaning of the heat exchanger. The method used is not the best, as a very powerful vacuum is necessary to do a good job. A commercial vacuum job is the best.
Many furnaces have clean outs where the vacuum can get better access to soot inside the heat exchanger. The video below covers the clean outs.
If the furnace has no clean outs, it can still be cleaned with some vigorous use of vacuum and compressed air. The video below shows how to do it.
To start the adjustments we will lower the pump pressure. This is to show the effects on combustion of the larger droplets that comes with low pressure.
We generally will increase pressure to get better combustion.
We generally will increase pressure to get better combustion.
In this one we will increase the pump pressure to 165#. This is done to make a finer spray of droplets. The small droplets are easier to burn because the small droplets take less heat to evaporate and thus to burn completely. Below are the results of these adjustments.
With this video, we reduce the nozzle size slightly to see if we can make up for the fact that the nozzle in the video above is now too large for the furnace because the higher pressure increases the amount of oil sprayed into the combustion chamber.
In preparation for a reduction in nozzle size, we must change the burner head to match the size of the smaller nozzle. The video below covers this operation.
In addition to matching the burner head to the smaller nozzle, the combustion chamber size must be reduced to match the nozzle. The video below covers how this is done.
In this video, We reduce the nozzle size to .4 GPH and make the burner adjustments.
The final video in this series goes over the conclusions of this exercise.