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Grundfos Recirculation Pumps

Recirculation pumps are the answer to waiting (and waiting and waiting) for the hot water to arrive where you need it. These excellent quality pumps from Grundfos are economical, easy to install, low-maintenance and they save valuable resources, too! Click here to see "typical" hot water system installation designs. Click here to see some options such as a timer or clip-on thermostat. See our brief overview of circulator systems and the FAQ's at the bottom of the page for even more suggestions.

We offer a complete range of circulator pumps for almost any application. UPS pumps are of the canned-rotor type, i.e. pump and motor form an integral unit without shaft seal and with only two gaskets for sealing which helps to extend pump life by keeping foreign debris out. The bearings are lubricated by the pumped liquid. UPS pumps are designed for circulation of liquid in heating and air-conditioning systems. Pumps with Bronze or Stainless steel housings are also suitable for circulation in hot-water service systems.

low prices on UP 15-18SUUP 15-29SU
most popular model
Typical Applications Include:
  • One- and two-pipe heating systems
  • Main pumps
  • Zone pumps
  • Boiler shunt pumps
  • Pumps for heating surfaces
  • Calorifiers
  • Underfloor heating systems
  • Solar heating systems
  • Heat pump systems
  • Geothermal heating systems
  • Heat recovery systems
  • Two-pipe air-conditioning systems
  • Pumps for refrigeration units
click any image below to jump directly to that item




Union Mounted Pumps - Stainless Steel

Most Popular Models - union adapter sold separately
UP 15-29SU
Pump Union Mount HP GPM @ 5' Price for 115V Price for 230V
1 speed pumps
UP 15-29SUC/TLC GU 125 1/12 6 $381.82 Not Available Enter a quantity and
UP 15-29SU GU 125 1/12 6 $282.38 $302.55 Enter a quantity and
UP 15-29SU/LC GU 125 1/12 6 $295.54 Not Available Enter a quantity and
3 speed pumps
UPS 15-35SUC GU 125 1/15 2.5/5/9 $322.28 Not Available Enter a quantity and
UPS 15-35SUC/TLC GU 125 1/15 2.5/5/9 $519.35 Not Available Enter a quantity and
UPS 15-55SUC GU 125 1/12 5/10/14 $528.53 Not Available Enter a quantity and
UPS 15-55SUC/TLC GU 125 1/12 5/10/14 $578.88 Not Available Enter a quantity and
Our top seller!
Note: We do not recommend ordering thermostats for use with Line Cord models - click here to learn why.

Flange Mounted Pumps - Stainless Steel

flange adapter sold separately
UP 15-29SF
Pump Flange Mount HP GPM @ 5' Price for 115V Price for 230V
1 speed pumps
UP 15-29SF GF 15/26 1/25 6 $281.97 Not Available Enter a quantity and
UP 15-42SF GF 15/26 1/25 7 replaced by UPS 15-35SFC Not Available Enter a quantity and
UP 26-96SF GF 15/26 1/12 16 $557.90 $563.38 Enter a quantity and
UP 26-99SF GF 15/26 1/6 27 $585.70 $590.81 Enter a quantity and
3 speed pumps
UPS 15-35SFC GF 15/26 1/25 2.5/5/9 * $321.61 Not Available Enter a quantity and
UPS 15-55SFC GF 15/26 1/12 5/10/14 * $485.74 Not Available Enter a quantity and
UPS 26-99SFC GF 15/26 1/6 16/24/28 $608.21 Not Available Enter a quantity and
What is the difference between union mount and flange mount?

Flange Mounted Pumps - Bronze

flange adapter sold separately
Pump Flange Mount HP GPM @ 5' Price for 115V Price for 230V
1 speed pumps
UP 43-75BF GF 40/43 1/6 38 $643.28 $650.87 Enter a quantity and
3 speed pumps
UPS 43-44BFC GF 40/43 1/6 20/38/45 $673.87 Not Available Enter a quantity and

Sweat Mounted Pumps - Bronze

UP 15-10B5
Pump HP GPM @ 5' Connection Price for 115V Price for 230V
UP 15-10 B5 1/25 1 1/2" $330.19 Not Available Enter a quantity and
UP 15-10 B5/LC 1/25 1 1/2" $351.06 Not Available Enter a quantity and
UP 15-10 B5/TLC 1/25 1 1/2" $427.67 Not Available Enter a quantity and
UP 15-18 B5 1/25 7 1/2" $330.90 $336.60 Enter a quantity and
UP 15-18 B5/LC 1/25 7 1/2" $349.68 Not Available Enter a quantity and
UP 15-18 B5/TLC 1/25 7 1/2" $441.95 Not Available Enter a quantity and
UP 15-18 B7 1/25 7 3/4" $350.06 $357.06 Enter a quantity and
UP 15-42 B5 1/25 9 1/2" $449.09 $457.96 Enter a quantity and
UP 15-42 B7 1/25 9 3/4" $450.57 $454.88 Enter a quantity and
LC models come with line cord (electric cord with plug) installed
TLC models come with timer and cord installed

Sweat Mounted Pumps with Integral Check Valve - Bronze

UP 15-10BUC5/TLC
Pump HP GPM @ 5' Connection Price for 115V
UP 15-10 BUC5 1/25 1 1/2" $369.70 Enter a quantity and
UP 15-10 BUC5/LC 1/25 1 1/2" $364.27 Enter a quantity and
UP 15-10 BUC5/TLC 1/25 1 1/2" $473.29 Enter a quantity and
UP 15-10 BUC7 1/25 1 3/4" $379.40 Enter a quantity and
UP 15-10 BUC7-LC 1/25 1 3/4" $391.81 Enter a quantity and
UP 15-10 BUC7-TLC 1/25 1 3/4" $471.97 Enter a quantity and
UP 15-18 BUC5 1/25 7 1/2" $370.86 Enter a quantity and
UP 15-18 BUC7 1/25 7 3/4" $380.28 Enter a quantity and
UP 15-42 BUC5 1/25 9 1/2" $488.76 Enter a quantity and
UP 15-42 BUC7 1/25 9 3/4" $495.60 Enter a quantity and
LC models come with line cord (electric cord with plug) installed
TLC models come with timer and cord installed

to many more quality circulator pumps by Grundfos


Flange Mounted Pumps - Cast Iron

Cast Iron pumps are for closed systems ONLY - flange adapter sold separately
UP 15-58FRC
Pump Flange Mount HP GPM @ 5' Price for 115V Price for 230V
1 speed pumps
UP 15-42F GF 15/26 1/25 15 $142.89 $149.63 Enter a quantity and
UP 26-64F GF 15/26 1/12 25 $349.31 $355.82 Enter a quantity and
UP 26-96F GF 15/26 1/12 21 Not Available $371.89 Enter a quantity and
UP 26-99F GF 15/26 1/6 30 $373.81 $379.99 Enter a quantity and
UP 43-75F GF 40/43 1/6 39 $451.85 $457.77 Enter a quantity and
UP 50-75F GF 50 1/6 39 $447.32 $452.37 Enter a quantity and
3 speed pumps
UPS15-42F GF 15/26 1/25 5/10/15 replaced by UPS15-58FC replaced by UPS15-58FC Enter a quantity and
UPS 15-58FC
"Super Brute"
GF 15/26 1/25 5/10/15 $144.33 Not Available Enter a quantity and
UPS 15-58FRC
"Super Brute"
GF 15/26 1/25 5/10/15 $151.89 Not Available Enter a quantity and
UPS 26-99FC
"Super Brute"
GF 15/26 1/6 16/24/28 $401.25 Not Available Enter a quantity and
UPS 43-44FC
"Super Brute"
GF 40/43 1/6 20/38/45 $458.50 Not Available Enter a quantity and
Rotated flanged housing

VersaFlo UPS 3-Speed Inline Commercial Wet Rotor Circulators - Cast Iron

flange adapter sold separately
UPS 32-40
Pump Flange
Mount
HP Flow Rate
(GPM)
Connection Ph Price for 115V Price for 230V Price for 460V
UPS 32-40/4 GF 15/26 1/3 9-52 1-1/4" 1 $996.47 $997.23 Not Available Enter a quantity and
UPS 32-40/4 GF 15/26 1/3 9-52 1-1/4" 3 Not Available $999.18 $994.57 Enter a quantity and
UPS 32-80/2 GF 15/26 1/2 9-67 1-1/4" 1 $1,018.16 $1,017.47 Not Available Enter a quantity and
UPS 32-80/2 GF 15/26 1/2 9-67 1-1/4" 3 Not Available $1,019.70 $1,015.09 Enter a quantity and
UPS 32-160/2 GF 40/43 3/4 9-76 1-1/2" 1 $1,278.12 $1,275.48 Not Available Enter a quantity and
UPS 32-160/2 GF 40/43 3/4 9-76 1-1/2" 3 Not Available $1,279.57 $1,278.74 Enter a quantity and
UPS 40-40/4 GF 40/43 1/3 13-85 1-1/2" 1 $1,183.70 $1,185.94 Not Available Enter a quantity and
UPS 40-40/4 GF 40/43 1/3 13-85 1-1/2" 3 Not Available $1,191.50 $1,185.26 Enter a quantity and
UPS 40-80/4 GF 40/43 1/2 13-120 1-1/2" 1 $1,217.40 $1,218.33 Not Available Enter a quantity and
UPS 40-80/4 GF 40/43 1/2 13-120 1-1/2" 3 Not Available $1,216.51 $1,219.54 Enter a quantity and
UPS 40-80/2 GF 40/43 3/4 13-105 1-1/2" 1 $1,243.55 $1,242.74 Not Available Enter a quantity and
UPS 40-80/2 GF 40/43 3/4 13-105 1-1/2" 3 Not Available $1,247.37 $1,249.68 Enter a quantity and
UPS 40-160/2 GF 40/43 3/4 13-110 1-1/2" 1 $1,821.81 $1,818.21 Not Available Enter a quantity and
UPS 40-160/2 GF 40/43 3/4 13-110 1-1/2" 3 Not Available $1,818.21 $1,815.76 Enter a quantity and
UPS 40-240/2 GF 40/43 1-1/2 13-130 1-1/2" 1 Not Available $1,968.66 Not Available Enter a quantity and
UPS 40-240/2 GF 40/43 1-1/2 13-130 1-1/2" 3 Not Available $1,967.84 $1,962.11 Enter a quantity and
Note: 460 V models are 2 speed only - speeds 2 & 3.

to many more quality circulator pumps by Grundfos


VersaFlow UPS 3-Speed Inline Commercial Wet Rotor Circulators - Bronze

flange adapter sold separately
UPS 32-40
Pump Flange
Mount
HP GPM @ 5' Connection Ph Price for 115V Price for 230V Price for 460V
UPS 32-40/4B GF 15/26 1/3 20/30/38 1-1/4" 1 $1,698.73 $1,692.67 Not Available Enter a quantity and
UPS 32-40/4B GF 15/26 1/3 18/25/39 1-1/4" 3 Not Available $1,703.72 $1,698.06 Enter a quantity and
UPS 32-80/2B GF 15/26 1/2 42/53/60 1-1/4" 1 $1,749.81 $1,759.70 Not Available Enter a quantity and
UPS 32-80/2B GF 15/26 1/2 47/55/60 1-1/4" 3 Not Available $1,755.94 $1,752.88 Enter a quantity and
UPS 32-160/2B GF 15/26 3/4 37/54/68 1-1/2" 1 $2,188.07 $2,188.25 Not Available Enter a quantity and
UPS 32-160/2B GF 40/43 3/4 50/56/70 1-1/2" 3 Not Available $2,178.26 $2,179.35 Enter a quantity and
UPS 40-40/4B GF 40/43 1/3 25/41/60 1-1/2" 1 $2,009.78 $2,012.47 Not Available Enter a quantity and
UPS 40-40/4B GF 40/43 1/3 30/38/64 1-1/2" 3 Not Available $2,017.68 $2,017.68 Enter a quantity and
UPS 40-80/4B GF 40/43 1/2 65/82/102 1-1/2" 1 $2,142.97 $2,132.98 Not Available Enter a quantity and
UPS 40-80/4B GF 40/43 1/2 68/80/110 1-1/2" 3 Not Available $2,142.79 $2,137.98 Enter a quantity and
UPS 40-80/2B GF 40/43 3/4 66/82/98 1-1/2" 1 $2,156.58 $2,168.64 Not Available Enter a quantity and
UPS 40-80/2B GF 40/43 3/4 70/80/95 1-1/2" 3 Not Available $2,166.66 $2,155.86 Enter a quantity and
UPS 40-160/2B GF 40/43 3/4 59/84/100 1-1/2" 1 $2,605.44 $2,600.11 Not Available Enter a quantity and
UPS 40-160/2B GF 40/43 3/4 65/75/100 1-1/2" 3 Not Available $2,597.67 $2,605.00 Enter a quantity and
UPS 40-240/2B GF 40/43 1-1/2 75/97/114 1-1/2" 1 Not Available $2,995.99 Not Available Enter a quantity and
UPS 40-240/2B GF 40/43 1-1/2 91/102/122 1-1/2" 3 Not Available $2,982.34 $2,984.70 Enter a quantity and
Note: 460 V models are 2 speed only - speeds 2 & 3.

CPVC Mounted Pump

Composite body - 115 volt - Replacement for UP15-15S and UP15-20S
UP 15-38SPA
Pump HP Flow Range Head Range Connection Price & Quantity
UP 15-38SPA 1/25 0-16 gpm 0-12 feet CPVC 1/2" x 3/4"
slip fit for spas
$228.30 Enter a quantity and

Thermostats & Timers

Description Price & Quantity
50.54-74 Timer control - fits any 1 speed* UP model (115v) - For pumps with date code 0527 or before - old style terminal box $92.57 Enter a quantity and
59.93-88 Timer control - New Style - fits any 1 speed* UP model (115v) - For pumps with date code 0528 or after - new style terminal box $92.38 Enter a quantity and
59.54-43 1/2" Copper clip-on thermostatic control (not adjustable) - 85°F - 105°F $37.75 Enter a quantity and
59.54-44 3/4" Copper clip-on thermostatic control (not adjustable) - 85°F - 105°F $37.81 Enter a quantity and
Notes: We do not recommend using clip-on thermostats with Line Cord models. Thermostats are somewhat (but not perfectly) temperature accurate. Click here to see the timer and thermostat install info and specs. These timers will work with 3-speed pumps, however, you must select a pump speed prior to using the timer.

Dielectric Flange Adapters with Isolation Valves

for bronze, cast iron and stainless steel pumps
Image of Dielectric Flanges with Isolation Valves
  • 1 complete set required per pump
  • Each set includes 2 each rotating flanges, lever handle full ported ball valves, EPDM gaskets, and dielectric sleeves - and 4 each 7/16" x 1-3/4" bolts with nuts
  • Flange adapters may not be needed if replacing existing pump
Dielectric Flange with Isolation Valve Sets
Part # Description Size Pump Connection Price & Quantity
591205 NPT Dielectric Isolation Valve Set (NOT for potable water) 1-1/4" GF 15 / 26 $29.98 Enter a quantity and
96806129 NPT Dielectric Isolation Valve Set - Safe for potable water 1/2" GF 15 / 26 $37.70 Enter a quantity and
96806130 NPT Dielectric Isolation Valve Set - Safe for potable water 3/4" GF 15 / 26 $48.24 Enter a quantity and
96806131 NPT Dielectric Isolation Valve Set - Safe for potable water 1" GF 15 / 26 $56.78 Enter a quantity and
96806132 NPT Dielectric Isolation Valve Set - Safe for potable water 1-1/4" GF 15 / 26 $63.09 Enter a quantity and
96806133 NPT Dielectric Isolation Valve Set - Safe for potable water 1-1/2" GF 15 / 26 $67.33 Enter a quantity and
96806134 Solder Dielectric Isolation Valve Set - Safe for potable water 1/2" GF 15 / 26 $37.54 Enter a quantity and
96806135 Solder Dielectric Isolation Valve Set - Safe for potable water 3/4" GF 15 / 26 $48.29 Enter a quantity and
96806136 Solder Dielectric Isolation Valve Set - Safe for potable water 1" GF 15 / 26 $56.51 Enter a quantity and
96806137 Solder Dielectric Isolation Valve Set - Safe for potable water 1-1/4" GF 15 / 26 $63.25 Enter a quantity and
96806138 Solder Dielectric Isolation Valve Set - Safe for potable water 1-1/2" GF 15 / 26 $67.28 Enter a quantity and
SUPER SALE! While supplies last

NPT Cast Iron Flange Options

For cast iron pumps ONLY
NPT Cast Iron Flange Set for use with cast iron pumps
  • 1 complete set required per pump
  • Each set includes 2 each flanges and gaskets - and 4 each 7/16" x 1-1/2" bolts with nuts
  • Flange adapters may not be needed if replacing existing pump
NPT Cast Iron Flange Adapter Sets
Part # NPT Pipe Size Pump Connection Price & Quantity
519601 3/4" GF 15 / 26 $16.03 Enter a quantity and
519602 1" GF 15 / 26 $15.95 Enter a quantity and
519603 1 1/4" GF 15 / 26 $16.05 Enter a quantity and
519604 1 1/2" GF 15 / 26 $15.94 Enter a quantity and
539605 1 1/2" GF 40 / 43 $21.91 Enter a quantity and
96409354 2" GF 50 $97.38 Enter a quantity and
91584910 2" GF 53 $103.79 Enter a quantity and
91584911 2 1/2" GF 53 $129.18 Enter a quantity and
91584912 3" GF 53 $147.90 Enter a quantity and
559601 2" GF 65 $139.59 Enter a quantity and
569601 3" GF 80 $156.95 Enter a quantity and
579801 4" GF 100 $282.29 Enter a quantity and

Bronze Flange Options

For bronze and stainless steel pumps
Image of NPT Bronze Flange Set
  • Safe for potable water
  • 1 complete set required per pump
  • Each set includes 2 each flanges and gaskets - and 4 each 7/16" x 1-1/2" bolts with nuts
  • Flange adapters may not be needed if replacing existing pump
Bronze Flange Adapter Sets
Part # NPT Pipe Size Pump Connection Price & Quantity
519651 3/4" GF 15 / 26 $54.97 Enter a quantity and
519652 1" GF 15 / 26 $55.04 Enter a quantity and
96409356 1 1/4" GF 15 / 26 $50.60 Enter a quantity and
539615 1 1/2 GF 40 / 43 $70.50 Enter a quantity and
96409355 2" GF 50 $374.72 Enter a quantity and
91584913 2" GF 53 $381.97 Enter a quantity and
91584914 2 1/2" GF 53 $451.82 Enter a quantity and
91584915 3" GF 53 $525.49 Enter a quantity and
569611 3" GF 80 $528.88 Enter a quantity and
96409357 4" GF 100 $768.54 Enter a quantity and

Bronze Union Adapter Options

For union series pumps
  • Safe for potable water
  • 1 complete set required per pump
  • Each set includes 2 each union connections and gaskets
  • Union adapters may not be needed if replacing existing pump
Bronze Union Adapter Sets
Part # Description Pump Connection Price & Quantity
529912 NPT Bronze Union Set - 3/4" Fips GU 125 Union $35.91 Enter a quantity and
529913 Solder Bronze Union Set - 1/2" sweat GU 125 Union $33.74 Enter a quantity and
529911 Solder Bronze Union Set - 3/4" sweat GU 125 Union $32.79 Enter a quantity and
519850 NPT Bronze Isolation Valve Union Set - 1/2" Fips GU 125 Union $44.47 Enter a quantity and
519852 NPT Bronze Isolation Valve Union Set - 3/4" Fips GU 125 Union $44.29 Enter a quantity and
519851 Compression Bronze Isolation Valve Set - 3/4" Nominal (7/8" OD) GU 125 Union $44.48 Enter a quantity and

Related Items & Accessories



Frequently Asked Questions

Q. "I'd like to have hot water without much of a wait. How can I do this?"
A. The two easiest solutions are:
A) A tankless water heater at the source.
B) A hot-water recirculation system. This consists of a small pump and a return line from your farthest fixture. The pump mounts near the bottom of your water heater along with a swing check valve (see diagram below).

Q. "Does a hot water recirculating system use up a lot of energy?"
A. Both options use energy. But not as much as most people think. On the recirculating system we highly recommend insulating all of your hot water pipes. Also having a timer and/or a thermostat will use even less energy. An electric tankless water heater doesn't use any energy when you're not drawing hot water.

Q. "Is the thermostat adjustable?"
A. The thermostatic control automatically turns the circulator off when the temperature exceeds approximately 105°F and back on when the temperature drops below approximately 85°F. The thermostat is not adjustable. You can click here to read more info about the thermostat.

Q. "Your timer seems expensive. Is it necessary?"
A. Most three-prong wall timers should work, but Grundfos makes a fantastic timer for their most popular model (#UP15-18SU). It can be set in 15-minute increments, mounts right onto the pump, and is the best timer we have ever seen. You can click here to read more info about the timer.

Q. "On your cast iron pumps you say that they are only for a closed system. What is a 'closed system'?"
A. A closed system is a recirculation loop for water (or other liquid) where once it is set up and running, no new liquid is introduced into the system. If new liquid is brought into the system it will bring air with it and over time this will rust out a cast iron pump.

Q. "Why don't you recommend ordering thermostats with the line cord pumps?"
A. Due to these pumps being pre-wired, they would require re-wiring in order to use the thermostats, so we recommend you purchase the pump, thermostat and timer separately when you want to use a thermostat.

Q. "Why do I need flanges/unions?"
A. The threads on the pumps are designed to attach only to the flanges or unions. There are many different sizes and types of pipe. Using flanges/unions means they don't have to make a different pump for every different size & type of pipe.

Q. "I am purchasing a replacement Grundfos pump. Next to the pump it states: 'one set required.' Must I (am I required to) order flanges/unions along with the pump or can I just order the pump?"
A. If it is an identical replacement Grundfos pump you certainly don't need to purchase flanges/unions again. The ones that you currently have "should" fit fine.

Q. "How is the quality of a Grundfos brand pump?"
A. We know of no finer made pump. Having said that we do want you to realize that every pump has a specific function. Meaning, for example, a circulating cast iron pump isn't generally for domestic drinking water. Every pump also has a specific flow rate, etc. so please don't assume that you can simply order the lowest priced Grundfos pump and that it will work for your situation. Grundfos is top quality but recognize that a $20,000 bicycle might not go as fast as a $15,000 car.

Q. "On your flanges/unions, what does 'ISO' mean?"
A. The ISO (isolation) flanges have a screwdriver shut-off built into them so the pump can be removed from the system without turning off the water supply.

Q. "Which pump would you recommend for most residential recirculation systems?"
A. Our most popular unit is the #UP 15-29SU (formerly the #UP15-18SU). It's a very quiet unit and uses less electricity than most light bulbs (65 watts!). For even more savings you can also incorporate a timer and/or thermostat.

Q. "You offer/show such a great selection and since I need the pump right away am worried that it won't ship right after I order it. How's your inventory on these?"
A. Over 95% of the pumps are always in stock and ship within 24 hours of us receiving your order (Mon-Fri).

Q. "What is the benefit of installing an optional timer or thermostat?"
A. Either one will save energy (and money). The timer only allows the pump to turn on at certain times. So if you only need hot water in the morning, you could set the timer for 6am to 8am. Then the pump would only recirculate the hot water during that time. The thermostat turns off the pump when the water in the pipes reaches a certain temperature. So once the water in the pipe is hot, the pump turns off. When the timer and thermostatic controls are installed together, in series, the circulator operates ONLY at the preset clock times specified by the user AND ONLY when the temperature conditions of the thermostat are met. That is, if either the timer control or the thermostatic control switch is open (off), the circulator will not operate.

Q. "What else would I need to install a hot water recirculation system?"
A. You'll need the pump & flanges/unions of course; a swing check valve, and pipe and pipe fittings to run the return line back to the pump. A timer and/or thermostat are optional. (click here for instructions and more info on these).

Q. "Are the Grundfos stainless steel pumps specified for potable hot water?"
A. Absolutely. They are an excellent choice for drinking water.

Q. "I want to install a hot water circulation loop so that I can get hot water quickly at my taps. My problem is that I have to pump it up about 20 feet and I only have 40 psi. Will a 1/2" return line work ok?"
A. You could even use 3/8" on the return line (after the last fixture). Best to go with 1/2" but there is no reason to use 3/4" pipe. When your system is entirely under pressure, while the Grundfos pump is "pushing" up, the water is also "dropping" down. Just make sure to get rid of ALL of air in your return line and design your system so that no air will be in your line.

Typical hot water system before a recirculation pump.

Common recirculation pump installation.

Close-Up of pump installation.

Notes on installation:

Now that you're going to have hot water in your pipes all the time we strongly recommend insulating your hot water pipes as well as the return line to avoid stand-by heat loss.

A 2" clearance should be kept between the hot and cold water lines.

Branches off of the main hot water supply should be kept as short as possible.

Local codes may require the installation of a hot water expansion tank for secondary pressure relief on cold water supply lines with check valves.

The pump should be installed with the motor shaft horizontal.

It is very important that there is no trapped air in the pipe or the pump. Unless you have extremely oversized the pump (which wastes a lot of energy), trapped air in the return line can damage the recirculation pump. With these Grundfos recirculating pumps, air removal from the pump can be accomplished by releasing air from the chrome slotted plug located on the front of the pump. IMPORTANT: This chrome plug must NOT be removed. This chrome slotted plug is to release air from the pump only, not from the entire circulation piping system. After the system is charged with water make sure the power to the pump is turned off. Position a bucket under the pump because water will begin to stream from the plug as the air is released. Slowly unscrew the chrome slotted plug counter clockwise, until small bubbles of air and water appear. As soon as tiny bubbles or water appear, stop unscrewing the chrome plug any further. Allow all the air to escape. When only water streams slowly out of the pump then you will know the air has been purged. Tighten the chrome slotted plug clockwise. To prevent air from collecting in the return line, slope all the pipes so air will flow to the high point in the return line and then put an air vent there so you can release the air periodically.

The return line can be installed either under the floor or in the ceiling.


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