Grundfos Recent Questions, Troubleshooting Help & Support

The Ranco ETC-112000-000 is a temperature controller commonly used for HVAC and refrigeration applications. To connect it to an indirect water heater, you can use it to control the temperature of the water in the indirect water heater's tank. Here's a general guide on how to do this: Please note: This is a general guide, and it's essential to follow the specific wiring instructions provided in the Ranco ETC-112000-000 user manual and the installation instructions for your indirect water heater. Materials and tools you'll need:

1. Ranco ETC-112000-000 temperature controller.
2. Indirect water heater.
3. Appropriate wiring and electrical supplies (cables, wire nuts, etc.).
4. Screwdrivers.
5. Wire strippers and crimping tools.
6. Electrical tape.
7. Safety equipment (gloves, goggles, etc.).

Steps to connect the Ranco ETC-112000-000 to an indirect water heater:

1. Read the Manuals: Before starting, thoroughly read the user manual of the Ranco ETC-112000-000 and the installation manual of your indirect water heater. This will ensure you understand the specific requirements and wiring diagrams for your equipment.
2. Turn Off Power: Ensure the power supply to the water heater and the Ranco controller is turned off at the breaker box to prevent electrical accidents.
3. Mount the Controller: Mount the Ranco ETC-112000-000 controller in a suitable location, typically on a nearby wall or control panel, within easy reach. Make sure it's securely fastened and level.
4. Wire Connections:
   • Connect the power supply wires (usually 120V or 240V AC) to the Ranco controller following the wiring diagram in the manual. Typically, you'll have two power wires: one for Line (L) and one for Neutral (N).
   • Connect the load wires from the Ranco controller to the electrical terminals on the indirect water heater that control the heating element(s). Refer to the water heater's manual for the correct terminals.
   • Make sure all wire connections are secure using appropriate connectors (wire nuts, crimps) and cover them with electrical tape to prevent any exposed wires.
5. Sensor Placement: Install the temperature sensor (usually included with the Ranco controller) into the water heater tank. Ensure the sensor is in contact with the water, as it will measure the water temperature.
6. Power On and Set Parameters: Restore power to the Ranco controller and the water heater. Configure the Ranco controller according to your desired temperature settings and control parameters. Refer to the Ranco manual for specific instructions on programming the controller.
7. Test and Monitor: Once everything is connected and set up, test the system to ensure it's functioning correctly. Monitor the water heater's temperature to make sure it maintains the desired level.
8. Final Check: Double-check all connections and ensure there are no loose wires or exposed connections. Secure the wiring neatly to prevent accidents or damage.

Microswitch in the controller not actuating because motor has failed or contacts have arced and welded shut or electronic control board fault.

sounds like a pressure cut off switch issue that senses when the water is turned off. https://www.google.com/search?q=grundfos+scala+2+doesn%27t+switch+off ..

It can only be three different things you've got air in the line or your pressure tank which is called the exterol tank could be losing pressure you might need a new air gauge pressure gauge on your tank or number three you have a leaky faucet somewhere or like I said air in the line if I had more details I could tell you exactly what it was

possibly overheating due to bad motor when it cools down it comes back on

It depends on the useage you put it to, but it is likely to be the flow sensor. It is called 'short cycling'.

Grundfos MQ3-35 booster pump short cycling - Love Plumbing ...

https://terrylove.com > forums > grundfos-mq3-35-boo... Jul 3, 2018 - Really appreciate this thread. I had an issue that the pump turned off every 10-20 seconds for just a brief moment. I solved this by increasing ... As an aside I was manager of a civic hall in Leighton Buzzard that hosted Grundfos Pumps annual presentation dinners and corporate events in the 1980s. https://www.google.com/search?q=Grundfos+MQ3-35B%3A+restarts+every+12+sec ..

I have the same problem and have found that the inlet check valve has a broken shaft in the center of device. It is a multi-piece plastic unit and it looks as if it is not quite seating and therefore the internal pressure leaks slowly back into my low pressure suction line. The pump will start and the pressure will build then shut off for about 30 minutes then cycle again. I am going to replace the check valve.

- changes in hydraulic conditions (clogged pipes, clogged filter, ...) - pressure switch failure - flow sensor failure (in normal condition the pump starts when the consumption is higher than 1.2 l/min or the pressure is lower than 2 bar) https://www.manualslib.com/manual/1569763/Grundfos-Mq-3-35.html?page=1#manual

Mine did that. Little known that the Grundfos MQ pump has a small pressure tank on the end. If the pressure is low and the air volume is therefore low, then any tiny loss of water results in pressure drop and pump cycles on. Check the pressure in the tank. This is not well described in the Grundfos service manual.To pump up the pressure bladder:1. remove the rear cylindrical cover (swift bash with a fist downwards)2. unscrew plastic cap on the end (about 2 inches diameter with tapered sides3. attach pump to schrader valve and pump up (22-25 psi according to service manual)Reassemble.Suggest teflon tape to schrader valve stem to try to create a secondary airtight seal.

Is it newly installed or has it been working for a while till you noticed it?

All you do is pop off the cover https://www.youtube.com/watch?v=okiwMnYiv88

Check the breaker. Check the reset on the motor. Wiring connections. If you have power to the motor & motor doesn't work...you need new motor.

Normally you can just replace the motor with out changing the entire unit. A new gasket should come with the new motor.

The bearings fitted to this pump are lubricated for life - if the noise is bearing related they will need to be replaced. If the noise is not from the bearings you will need to establish the cause - possibilities are:
Cavitation (sounds like frozen peas inside the pump!) caused by restricted suction - check for blocked strainer etc.
Foreign matter in the pump....
Loose impellers
Sometimes a piece of wood or a large screwdriver used as a stethoscope can be very handy in determining where abouts in the pump the noise is coming from.
Given more specific information I can suggest the next course of action.
Good luck
Mike G

Sounds as if it is siezing up, replace for new.

Replace it.

Might be bad single-handled faucet cartridge http://waterheatertimer.org/Water-heater-recirculation-system.html http://waterheatertimer.org/Crossover.html Gene If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7