Lukewarm/fluctuating Hot Water with Recirculation Pump

You have our "Smart Pump". Do you know what mode you are in, Smart or Pulse?

If the Mode LED is solid, you are in Smart Mode. It will learn your usage for the week and bring on the pump the following week during those times. It will learn week to week, so if you change your habit, then you might want to be in Pulse Mode.

If flashing, you are in Pulse Mode. You have the option to have the pump run 1-10 minutes ( factory set to 3 minutes ) and then off for 10 minutes.

The arrow on the casing if pointing down, so that is your direction of flow.

Please give Taco Technical Services a call during normal business hours Mon-Fri 8am-5pm EST 401-942-8000 and just ask for Technical Services.

The external sensor needs to be wired to the controller in order for the pump to work.

In the Smart Mode, the sensor will sense a rise in temp and record it for the following week.

As long as the pump was properly sized and installed correctly, it should last awhile. Unfortunately, hard to put a time table because it depends on to many variables.

Was the system purged of air? Can you take an amp reading off the motor. The 008 should draw 0.84 amps under normal conditions.

It looks like you have a hybrid water heater (heat pump design with back up electric elements).

This type of recirculation logic (continuous pulse) is usually not recommended by the manufacturers of hybrid style water heaters. These water heaters have such a long recovery time when running in heat pump mode that when the pumps run excessively, it cools down the water heater too quickly.

The job of a recirculation system circulator is to not pump a ton of hot water around the house, it just needs a trickle to keep the pipes "primed". It sounds like your pump is working fine.

With hybrid water heaters, it is suggested to use an "on-demand" type of recirculation logic. Smart pulse as @SteveSan was suggesting is better with what you already have while the Genie is better for the operation and recovery of your water heater.

When changing it to pulse, it is going to take 7 days to learn your patterns. For these next 7 days, it will still operate in the pulse mode until it learns so you will not notice anything different right away.

What brand water heater do you have? I would like to look into the information as to their recommendations.

Page 13 of the installation guide with this model does not recommend a recirc loop in order to maximize the economy of operation. However, these instructions were written in 2015 and maybe they have done other research and testing with their units and have recommendations.

Also on this page, which may help more with your water temperature fluctuations is maybe adding a Thermostatic mixing valve as they show in the middle of the instructions.

When changing it to pulse, it is going to take 7 days to learn your patterns. For these next 7 days, it will still operate in the pulse mode until it learns so you will not notice any difference for at least a week, so you may need two weeks before the change

Hi, I do not see a check valve in the recirc line. Is there one in the pump? If not, you probably are getting flow backwards through the reirc line when water is used, which will give temperature fluctuations.

Yours, Larry

A bypass would need to be piped. I would follow what @SteveSan says above for now. Hopefully, that should put you on the right track.

Is this pump "mounting specific"? By that I mean, that most pumps with a check valve in the discharge can not be mounted with the check valve pointing down which would allow the check to remain open all the time. I would check the mounting directions to see if the pump needs to be rotated so the water flow is up and not down as it is in your case. I also read somewhere that the check valve is an optional item. Your problem may be that the pump is mounted incorrectly and will have to re-piped to get the flow direction correct.

what had it stuck open?. Dirt or scale? Perhaps a y strainer upstream would help.

Hi, It looks like there's room under the pump to install a threaded spring check. To @Teemok 's point, a plumber could not afford so many free service calls, all while looking bad and badder to the client. With the valves you have, getting to a threaded spring check wouldn't be very difficult if it needed service. Could be that sediment from the water heater is making its way to the present check. If so, the problem is not going away.

Yours, Larry

doesn’t matter what type of spring check you use, debris, and just a single particle can hold them open.

If you install sensitive valves in plumbing or heating applications, a y strainer is cheap insurance for protecting them and eliminating frequent cleaning or replacement.

That same neoperl check used in circulators is also used in seperate spring check bodies. It is 3 pieces to be serviceable and inserting it into the body locks the 3 pieces together.

I had an IFC pump that gave me fits. It happened that the IFC was installed backward in the volute. Gasp, now I check to make sure it is installed correctly. Why is experience such a painful teacher?