Condensing Gas Boilers FAQ

Singular Boiler Products

An A5 error code indicates that the boiler's water pressure is running low.

  • The most likely time that you may see this error code is just after the boiler has been installed and run, and it's typically an indication that the water fill procedure wasn't correctly followed.
    To rectify this, please refer to the "System Filling" section of your installation manual.
  • If the issue remains ongoing even after ensuring that the boiler's water pressure is correct, it could be the case that water is being lost in the overall heating system somewhere. We recommend that a contractor examine the boiler and the home's heating system for evidence of water leakage.

If you no longer have the printed copy of the manual, you can download an electronic version from this page.

You will notice two icons to the left of the boiler's display screen. One is a Radiator and the other is a Faucet:

  • Radiator Icon: This icon is always illuminated when the boiler is powered on. If you need to adjust the space heating temperature, press the MODE button and the display screen will change to show the current set point. The + and - buttons can then be used to adjust the temperature setting. Once you have made the adjustment, simply wait for 5 seconds and the control will revert back to normal operation and the Radiator icon will remain illuminated.
  • Faucet Icon: The only time that this icon illuminates is when the user manually goes into the settings to change the temperature of the domestic hot water. If you want to adjust the temperature of the domestic hot water, press the MODE button until the Faucet icon illuminates. The + and - buttons can then be used to adjust the temperature setting. Once you have made the adjustment, simply wait for 5 seconds and the control will revert back to normal operation with the Faucet icon turning off and the Radiator icon turning back on.

Early production runs of the Singular boiler inadvertently included those wires, and they will be removed from current and future production of the product.

In short:

  • The two blue "Air Handler" wires have NO purpose at all.
  • Please do NOT attempt to connect them to anything or cut them off. Simply tuck them neatly out of the way.
  • The Singular boiler CANNOT be connected to an air handler.

At the bottom of the boiler you will see two brown wires labelled "Zone Control Wire". Please connect your thermostat, or zone control's end switch, to these wires.

For further details and wiring diagrams, please download the latest manuals from this page.

This is a perception that is most commonly noted by owners that have recently switched to a combi-boiler or a tankless water heater after moving away from using a heated storage tank to produce and store Domestic Hot Water (DHW).

Here's why:

Heated Storage Tanks - The water contained in such a water heater is being heated throughout the day and night, regardless of whether you are using it or not.

The benefit of course, is that the stored water is already hot and ready for use at any time.

However, that means that energy is being used just to keep a large supply of hot water on standby. You are paying to heat and store water all the time, just to use it sporadically through the day.

In addition to the ongoing energy use, you will also only be able to use as much hot water as the tank can store, and once the hot water is depleted, you will need to wait until the fresh cold water has been heated up and ready to use.

Combi-Boilers & Tankless Water Heaters - These types of water heating products only produce hot water when the owner opens a hot fixture somewhere in the home.

This means that no hot water is stored in the product, and so when you open a fixture in the home the water heater will ignite and then start heating the cold water that is flowing through its heat exchanger now. That does mean that there is a small delay in the delivery of hot water to the fixture, and if you previously used a heated storage tank you may notice it.

The benefits though, are significant:

  • You are only paying for energy while the product is activated and producing hot water on-demand. When you close the hot water fixture, the product is going to shut down and go back into standby mode.
  • You are not limited to a fixed amount of hot water that will deplete and then run cold. As long as you have a hot water fixture open and the product has activated, you will have endless hot water from that fixture until you close it.

Plumbing Distance:

Regardless of whether you are using a heated storage tank, a combi-boiler, or a tankless water heater to produce your home's hot water, there is another delay that must be recognized.

There will still be a delay in the delivery of hot water as the plumbing between the product and the fixtures will contain cold water that will need to be pushed ahead of the hot water that's heading towards the open fixture.

Simply put: The longer the run of plumbing, the longer it will take for the hot water to arrive where it's needed.

Potential Solutions

For the majority of users, the small delay in hot water being produced and then reaching their hot fixtures is of no concern. It is a normal dynamic of hot water that is produced by a combi-boiler or a tankless water heater, and the owner is instead focused on enjoying the lower energy costs!

  • If you have a fixture that is particularly far away from the water heating product, and it's one that you frequently use and the delay is problematic for you, then you could use an electric mini-tank water heater as booster. These water heaters are typically 120v and should be installed close to the distant hot fixture and in-line between the main water heating product and the distant fixture. For further details regarding our family of Tronic 3000T electric mini-tank water heaters, please visit this page.

  • If you would prefer to reduce the wait time for hot water at all hot fixtures in the home, then we recommend consulting a licensed plumber to discuss the options for installing a recirculating hot water plumbing arrangement. Please visit this page to search for a contractor in your area. Typically one loop of hot water plumbing will leave the water heating product, travel around the home, and then back to the product. Short plumbing lines to each hot water fixture will then branch off the main loop. A pump and a timer will be used to circulate the water around that loop occasionally, which will also activate the combi-boiler or tankless water heater, and leave hot water in the plumbing loop around the home. The next time you open a hot water fixture, you will have less of a wait time for cold water to flush through, as it is pre-heated from the last time that the recirculation pump ran.
    Important! Before deciding to install a recirculation loop, be certain that your combi-boiler or tankless water heater can safely be installed in such an application. Some models are designed to be supplied with cold water only and may be damaged if supplied with heated water that is returning from a circulation loop. Consult the literature that came supplied with your product. If you no longer have the printed literature that came supplied with your product, an electronic copy can be downloaded from our manuals download page.

Warning! Water temperature that is over 120of (50oC) can cause immediate scalding, burns, or even death. As with all products that produce domestic hot water, we recommend setting the temperature as low as possible while still satisfying your needs at the hot water fixtures in your home.

To Adjust The DHW Output Temperature:

  • Press The "Mode" button the front of the display control until the "Faucet" icon is illuminated.
  • Use the "+" or "-" buttons to select your desired DHW temperature (please see the Warning note at the top of this section!).
  • The control will return back to normal operation after several seconds if you do not push any buttons.

For further details regarding all of the above maintenance topics, please refer to the User Manual and Installation Manual that came supplied with your boiler.

If you no longer have the hard copies, we have made electronic copies available to you for download via this webpage.

Yes, selecting the "H7" mode will allow you to see the temperature of the DHW as it leaves the boiler and heads to your home's fixtures.

To Access "H7" Mode:

  • Press the "Mode" button repeatedly until "H7" is displayed on the screen.
  • The display will alternate between showing "H7" and the actual temperature of the DHW from the boiler.
  • The control will return back to normal operation after several seconds if you do not push any buttons.

For further details regarding all of the above maintenance topics, please refer to the User Manual and Installation Manual that came supplied with your boiler.

If you no longer have the hard copies, we have made electronic copies available to you for download via this webpage.

Unless you have used the "Mode" button to temporarily move into a different mode, the reading that is shown on the boiler's display at all times during normal operation is the temperature of the water that is being supplied out to the home's heating system.

If you would like to see the temperature of the water that is returning back to the boiler from the heating system, you will need to go into "H9" mode.

To Access "H9" Mode:

  • Press the "Mode" button until "H9" is displayed on the screen.
  • The display will alternate between showing "H9" and the temperature of the heating water returning to the boiler.
  • The control will return back to normal operation after several seconds if you do not push any buttons.

For further details regarding all of the above maintenance topics, please refer to the User Manual and Installation Manual that came supplied with your boiler.

If you no longer have the hard copies, we have made electronic copies available to you for download via this webpage.

Warning! The gas conversion process must ONLY be carried out by a service person who is qualified to work on gas combustion equipment, and possesses a properly calibrated gas combustion analyzer. If you are in need of a qualified service person in your area, please use this contractor search page.

No, we do not produce variants of the Singular that are specific to gas types. All Singular boilers come setup and ready for installation into NG applications, but we also include a free of charge LP gas conversion kit in the boiler's packaging too.

The correct installation of the conversion kit, and subsequent setup of the boiler, will require a gas-qualified service person with a calibrated combustion analyzer, a #2 Phillips screwdriver, and a 5/32" (or 4mm) Allen wrench.

Illustrated step by step instructions of the gas conversion procedure are provided in the Installation manual that came supplied with your boiler. If you no longer have the hard copy, we have made electronic copies available to you for download via this webpage.

Warning! The DIP switches are used to control certain functions and limits of the boiler, and must ONLY be adjusted by a service person who is qualified to work on gas combustion equipment. If you are in need of a qualified service person in your area, please use this contractor search page.

For specific details regarding all of the DIP Switch settings and procedures mentioned below, please refer to the Installation Manual that came supplied with your boiler. If you no longer have the manual, we have made electronic copies available to you for download via this webpage.

The DIP switch block is mounted on the boiler's main circuit board, and is numbered 1 through 8 (top to bottom):

  • Switch #1 (labeled "FTC"): Enables/Disables the exhaust temperature limit (Enabled = switch in the On position / Disabled = switch in the Off position). This switch comes from the factory set to Off and limits the exhaust temperature to a maximum of 149° F (65° C), allowing for the use Schedule 40 PVC exhaust venting. In applications where the exhaust temperature will be higher than 149° F (65° C) the switch must be set to On and vent materials approved for those higher temperatures MUST be used. For full details, please refer to the Installation Manual.
  • Switch #2 (labeled "PROGRAM"): This is the data change mode switch, and comes from the factory set to Off. When the installer is ready to program the boiler's control to set the Outdoor Reset heating curve and also the elevation that the boiler is installed at, this switch must be set to On to put it into the programming mode and then switched back Off to lock in the changes.
  • Switches #3 and #4 (labeled "EX 1" and "EX 2"): The position of these two switches is dependent on the diameter and length of the exhaust flue installation, and MUST be set by the installer while referring to the table that is included in the Installation Manual.
  • Switch #5 (labeled "N/A"): Not used. No adjustment needed.
  • Switch #6 (labeled "MIN"): Minimum heat capacity switch. MUST be used by the installer when using a combustion analyzer to finalize the setup of the boiler.
  • Switch #7 (labeled "MAX"): Maximum heat capacity switch. MUST be used by the installer when using a combustion analyzer to finalize the setup of the boiler.
  • Switch #8 (not labeled): Not used. No adjustment needed.