Can I replace defective parts with similar product types?
No, installing any other replacement parts other than original will compromise the warranty of the boiler and will result in non-compliance with UL requirements.
Where are the products warehoused?
The NextGen Boiler and parts are warehoused and shipped out of Schaumburg, Illinois located approximately 30 minutes west of ORD Airport.
How do I size the boilers for the building?
It is highly encouraged to perform a calculated heatloss to determine the NextGen Boiler model needed to provide heating for the application.
I have an application that requires 75,000 BTU heatloss. Could I pipe the NextGen Boiler in parallel to achieve this output?
Yes that is acceptable. However, a third party control will need to be incorporated to turn on both boilers. There is no communication output to activate the second boiler. We highly recommend with this option that both boilers are set at the same supply water temperature. Do not use outdoor reset with parallel boiler piping. Another option would be to separate the boilers in zones and bring the PEX piping to separate manifolds located in the building. This can reduce long leader lengths of PEX piping.
How do the high temperature limits get replaced?
Both of the manual and auto reset high limits are surface mounted components. Unlike some competitor boilers, they do not require the boiler to be depressurized and drained in order to replace them.
What are the high limit trip points?
The auto reset high limit has a trip point of 160°F. The manual reset high limit has a set point of 200°F.
What are the temperature capabilities of the NextGen Boiler?
The boiler can be operated on application requiring water temperatures between 85°F to 140°F.
What happens if there is a failure of a heating element?
Element failure is very rare and can be attributed to poor water quality. However, in the case of element failure the heat exchanger should be replaced with the exact kW type that matches the kW output of the boiler. Ex) A 14.4 kW boiler should have a 14.4kW heat exchanger replacement.
Is there a recommended pH level?
The pH level is very important to test. This will extend the longevity of the boiler while maintaining reliability and efficiency. The best pH for NextGen Boilers is a level between 6-7. Too high of pH can corrode components.
What is the total capacity of the NextGen Boiler? How about the heat exchanger?
The total capacity is 1.06 gallons whereas the heat exchanger is .5 gallon capacity.
Is Propylene Glycol acceptable to use?
Yes, keep in mind that the viscosity of the freeze protection fluid can result in lower BTU output and also can change the flow characteristics of the circulator pump. Do not use more than 50% ratio of propylene glycol.
Will the primary circulator pump be suitable for all radiant applications or designs?
The pump is not a one size fits all. Each designer should take into account the Disposable/Available Pump Head curve found on page 4 of the NextGen Boiler installation manual. Failure to comply with this curve may result in problems with heating the application properly. Depending on how the system is designed, the primary pump can handle most applications where a 20 Delta T is used. Note that the 14.4 kW model likely will require a secondary pump when installed with hydraulic separator or closely spaced tees.
What happens to the boiler upon a power outage?
The boiler will resume normal operation once 240 VAC power is restored. The control panel will continue to hold the memory of the pre-programmed set points set by the user.
Does the staged rotation of the heating elements take place when the number of active heating elements is programmed to reduce to only two active heating elements?
Yes, the software in the control panel will continue to power the active heating elements in a staged rotation sequence as programmed in the Advanced Settings. This will allow equal wearing of the element regardless of how many elements are active.
Does the circulating pump continue to operate once the programmed warm weather shutdown temperature is reached?
No, the circulating pump is turned off when the outdoor sensor reaches the same programmed warm weather shutdown temperature on the control panel.
How do I replace the expansion tank in case of failure?
The boiler will first need to be drained. The electrical circuit(s) will need to be powered off in the electrical panel and then disconnected from the boiler. Consequently the low voltage circuits need to be removed as well. Then remove pressure and drain accordingly to remove the boiler from the wall. An option method for removal is to remove the expansion tank holding bracket. There are two screws located on each side of the boiler. The pipe connections will first need to be removed in order to slide the tank down from the back of the boiler.
What is the pre-charged pressure value with the expansion tank?
The expansion tank is located behind the boiler and is pre-charged to a value of 14 psi. To check or adjust pressure, there is a Schrader valve located behind the lower portion of the wall plate that separates the internal components from the expansion tank. It is located just in front of the inlet pipe connection to the expansion tank.
Is the boilers expansion tank a bladder or diagram type?
The flat expansion tank is a diagram type and runs vertically from seam to seam internally in the expansion tank.
What is the acceptance factor of the expansion tank?
Should the NextGen Boiler unit be cleaned prior to operation?
It is always recommended to first power flush the boiler and the related hydronic components prior to the final filling. Water quality for a closed loop hydronic is crucial to longevity and performance of the system. Cleaners such as Sodium Phosphate to de-grease or the use of Fernox can be used to help treat the system. Remember to clean out the magnetic filter prior to final filling and pressuring the system.
What about PEX piping without oxygen barrier tubing, what effects does this have on the boiler or system?
Reducing air in any system will help keep water quality in check and long lasting system performance. We highly recommend PEX tubing with an oxygen barrier.
How is the watt output of each element determined?
Simply take the model number and divide by three to obtain wattage of each element. Ex) NextGen Boiler -12 divided by 3 = 4kW heating elements
Upon replacement of the control panel, does the preset need to be programmed?
The control panel must be programmed through advanced settings to match the boiler kW model and the heating curve (if applicable).
Will the control panel work with all boiler models?
Yes, The control panel is configured to work with all kW sizes. However, after installation the control panel will need to be programmed in Advanced Settings to match the kW of the boiler model.
What is the house symbol for on the control panel?
The house symbol when lit indicates a call for heat from the thermostat. If there is a call for heat and either an open connection on the off peak or outdoor sensor the house symbol will blink. Also, when using outdoor compensation the house symbol will blink when the outside temperature is above the preset curve.
How does the pressure switch get replaced?
The boiler will need to be depressurized and drained for replacement. Simply remove the wiring connection and then unscrew the pressure sensor to replace. Failure of this component is rare.
How does the flow sensor operate?
The flow sensor works with a very high level of accuracy without moving parts or an impeller. It signals back to the control panel the flow rate in GPM and the supply water temperature (SWT)
How do you replace the flow sensor if it fails?
The sensor has no moving parts and is not sensitive to debris therefore failure of the sensor is highly unlikely. However, if for some reason it needs to be replaced either the internal components can be removed and replaced from a new flow sensor or the entire component can be replaced by removing the pins and working the device out of the piping.
I noticed on initial start up the symbol for the circulating pump blinks. Is that normal?
Yes, The boiler first needs to ensure the minimum gallons per minute flow rate is moving through the boiler before allowing the elements to come on. Refer to the specification table for the minimum flow rate per model.
Can the GPM flow rate of a zone or circuit be monitored on the control panel?
Yes, the user can toggle the control panel arrows to the GPM indicator and will indicate the flow in gallons per minute (GPM) Adjust the zone valve accordingly to the designed flow rate for that circuit. This is a very useful feature for the installer. Also, if 240 VAC is supplied to the control panel, the installer can power up the control board and use this feature to adjust proper flow rates at time of installation.
Does the boiler need a separate circuit for the circulating pump?
Yes, the primary or internal circulating pump will need to be powered with a separate 120 VAC 15amp circuit breaker. The connection point for this circuit is located on the pump board located on the top left portion inside the boiler.
If I install the boiler with primary/secondary piping, will a separate electrical circuit be necessary?
No, the boiler is equipped to handle the secondary pump from the Pump 2 connections located on the pump board. Although the installer still needs to wire to the secondary pump from these Pump 2 connections. Note that the circuit is protected by a 2 amp fuse and may have limitations on larger circulators with higher amp ratings.
What is the OP connection on the control panel used for?
The OP connection can be integrated with an electric utility OFF PEAK or Time of Use (TOU) program. This enables the utility to remove the boiler's kW load off of their peak or enable the operation of the heating systems during specific times of the day. In turn the customer receives discounted electricity. The OP circuit could also be utilized to shut the boiler off using any dry contact integrated in other applications.
What electrical breaker size is needed for the NextGen Boiler-12?
Please refer to the installation manual or specification literature for proper sizing. The electrical contractor is responsible for ensuring that all circuits are properly sized to meet the National Electric Code.
How does the pressure differential bypass valve work?
The boiler will not start when the pressure in the system is not high enough. For example: There are 6 radiant circuits and 5 of them have thermostatic valves switched off, a large resistance in the system will occur that may prevent the activation of the boiler. In this situation, the bypass valve will provide sufficient flow through the boiler and correct operation of the system. The valve is pre-set in order to work with minimal resistance. By adjusting the valve, you can lift the pressure barrier but we recommend that it is left at the factory settings.
Why is the pressure sensor located lower instead of up higher in the boiler?
The sensor is designed to measure the pressure in the system. Placing it directly in front of the heating unit would provide false reading because of the internal components of the boiler that also have an impact on the size of the pressure (pump, elbows on tubes and so on...). The sensor is there to switch off the boiler when the system pressure falls below 0.7psi.
What is the pressure drop across the NextGen Boiler?
The pressure drop across the boiler is configured with the pump curve to give the designer/installer the available or disposable pressure drop. Please refer to this curve to configure radiant design using the primary or secondary pump.
I noticed the picture on the boiler literature does not have a pressure/temp gauge installed on the system. How does an installer determine pressure in the hydronic system?
A pressure/temp (P/T) gauge can certainly be installed in the piping. Manufacturers often includeP/T gauges with their manifolds as well. The NextGen Boiler is unique in that it has a pressure sensor integrated in the boiler. The pressure reading in PSI can be viewed on the control panel. This will eliminate the need to purchase and install a pressure temp gauge thus saving on labor. Note that in order to read the pressure in the system, the boiler will first need to be powered with 240 VAC power.
