CircuitSolver FAQ’s

Click on any question below to expand the answer.

What are the primary advantages of a thermostatic balancing valve over the traditional manual balancing valve and pressure independent balancing valves?
The two primary advantages are:
  1. Thermostatic balancing valves are temperature devices directly addressing a temperature problem;
  2. They are dynamic and continually changing as conditions change resulting in “no callbacks,” energy savings, and water conservation.

What are the advantages of CSU—Circuitsolver with the union and an optional check valve?
The CSU is an integrated solution incorporating a union with an O-ring face seal and an optional check valve. By having the union and check valve integrated, you save cost and labor, reduce the number of potential leak points, and have a more compressed, reliable assembly, and review.  Click here to view our comparable cost savings breakdown.

What are the tradeoffs between a fixed vs adjustable thermostatic balancing valve?
Presently there are two types of thermostatic balancing valves, fixed (CircuitSolver®) and adjustable.  Fixed valves offer the following advantages:
  1. “Tamper-proof,” no unnecessary adjustments by non-qualified personnel resulting in an unbalanced hot water system.
  2. High CV compared to the adjustable, resulting in low-pressure drops (sometimes by a factor of four) when requiring higher flow rates to overcome high heat loss.

Can CircuitSolver® be installed in any orientation?
Yes, CircuitSolver® valves will function properly in any orientation. However, valves with an integrated check valve must be installed with the flow arrow pointing in the correct direction (towards the return line).

What is the GPM & ∆P when the valve is closed, open, and at the design CV?
When the CircuitSolver® valve is closed, it does not shut off entirely and still allows a fraction of a gallon per minute flow. This will enable it to better sample upstream water temperature changes and facilitate high-temperature sanitizing cycles of the domestic hot water system. The two formulas below allow you to calculate GPM and ∆P based on knowing two of the parameters. Please reference the formulas below.


      CS Formula GPM  300x60 - CircuitSolver FAQ’S           CS Formula P  300x157 - CircuitSolver FAQ’S

What is the highest temperature a CircuitSolver® valve can handle?
CircuitSolver® valves are rated to a maximum temperature of 250°F (121°C). All the valves can easily handle more than 212°F (100°C) which is the boiling point of water and is higher than any water temperature in a domestic hot water system.

What is the highest pressure a CircuitSolver® valve can handle? What is the minimum pressure drop required for the CircuitSolver® to operate?
The CircuitSolver® is rated for a maximum pressure drop of 200 psi. CircuitSolver® is a self-actuated temperature device. It changes its position based on water temperature. CircuitSolver® requires no minimum pressure to operate.

What materials are used to produce CircuitSolver®?
CircuitSolver® valves are made entirely of stainless steel. ALS has tested the valves to confirm that they meet NSF/ANSI/CAN 61 & 372 requirements.

What certifications does CircuitSolver® have?
  • NSF/ANSI/CAN 61 & 372, certified by ALS; mandated by most states for potable water systems
  • Section 116875 of the California Health & Safety Code, certified by Truesdale
  • Mass Board Approval
  • American Iron and Steel, Buy America, and Buy American Compliant

What is the difference between NSF 61 and NSF 372?
NSF 372 is a low lead standard and is a subset of NSF 61. In addition to NSF 61, requiring components to have low lead (NSF 372) it also tests potentially harmful chemicals leaching into the domestic hot water system from non-metallic parts such as O-rings, diaphragms, plastic parts, sealants, etc. NSF 61 is a mandated certification in most states.

How do you size CircuitSolver® for the recirculation system?
Since the flow through a CircuitSolver® only has to be enough to offset heat loss in piping, which is typically a very low flow, we recommend using valves that are the same size as the recirculation line.

How do you select the correct set-point for a CircuitSolver®?
As described in our CircuitSolver Brochure, the “XXX” in the model number is the desired return line temperature. For example, if you want the return temperature to be 110°F, and the line size is ¾”, you would select a CS-3/4-110. We have enhanced the product line to include an integrated union, CSU with an optional check valve CSU – X-XXX-CV1, and assemblies with ball valves, the CSUA and ball valves plus a strainer, CSUAS. Refer to the CircuitSolver Brochure to see the model selection chart.

Does CircuitSolver® shut off tightly?
No, a small bypass (0.2 GPM) is built into the CircuitSolver® even when “closed.” This is done so that the distribution branches are always providing flow back to the pump such that it is never “dead-headed.”

How do you recommend installing CircuitSolver® valves?
As shown in our installation and maintenance instructions, there should always be unions and shut-off valves installed before and after each CircuitSolver®. This provides more convenient access to the valve for future service. Since the water is almost always filtered/strained earlier in the loop, the addition of a strainer ahead of CircuitSolver® would be redundant. If no other strainer is present, consider installing one by each valve. See the Specifications & Installation Instructions page for more details.

Why are check valves sometimes used after a balancing valve before the branch/riser enters the return line?
Generally to prevent return backflow into the branches or risers under certain conditions such as a negative pressure due to fixtures being open to the atmosphere near the return line.

How do you size the recirculation pump when using CircuitSolver®?
Use the industry-standard plumbing engineering guidelines, for example, as shown in the ASHRAE handbook, to calculate system heat loss and system friction loss which will facilitate pump sizing. There is no need to oversize the pump to compensate for other factors.

What warranty is offered with the valve? What is the estimated service life?
The CircuitSolver® product line offers a 3-year warranty. Master mechanical mixing valves have been in service for many years. These mixing valves have the same type of actuator (paraffin wax motors) as CircuitSolver® valves. These mixing valves generally perform very well and have a proven history of reliability. Since a CircuitSolver® valve is all stainless steel, it can be expected to perform even better than these valves, which are generally brass. We estimate the typical service life at over 20 years.

I need to flush and sanitize my lines, will CircuitSolver® valves be able to handle the high temperatures?
Yes, all CircuitSolver® valves are rated to a maximum temperature of 250°F (121°C). All the valves can handle more than the highest water temperatures that will ever be encountered in domestic hot water systems.

My lines are prone to calcium buildup, will CircuitSolver® valves clog?
The actuator in CircuitSolver® is powerful enough to force out any buildup in its path when it modulates. The actuator develops over 40 lbs. (18kg) of thrust which is more than enough to break loose any mineral buildup and stainless steel is highly resistive to mineral buildup. It is also important to keep in mind that the mineral buildup is not very likely to occur in CircuitSolver® since it mostly occurs where there is a heating surface or a minimal leak. Read the Effects of Hard Water on CircuitSolver® for more information.

Do I need to use a strainer with CircuitSolver®?
In general, no. Since the valves are used in potable water systems, particles in the water should already be taken care of. A strainer is recommended if there is a history of particulates causing problems in the domestic hot water system. We offer CircuitSolver® configurations pre-assembled with a strainer (CSUAS) for systems that need it.

What facilities have CircuitSolver® valves been installed at?
Please view our Installations page to see examples of where CircuitSolver® has been installed.

How much does a CircuitSolver® cost?
When factoring in the labor it takes to manually balance a system and the initial cost of balancing valves, CircuitSolver® provides significant savings over traditional methods. Specifying the CSU CircuitSolver® with an integrated union and optional check valve provides additional savings and increased reliability. Contact a sales representative in your area for pricing and delivery.

What are the reasons for recirculating the cold water in a Domestic Water System?
Domestic cold-water systems are being recognized more and more as posing health risks to occupants—high water temperatures in the Legionella range, stagnant water due to dead legs, low water usage; lack of free chlorine distribution; bacteria buildup due to low or no moving water—recirculating the cold water will help mitigate these potentially harmful conditions. VHA 1061 guidelines recommend recirculating cold water.

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