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45 Series (45H/45HI) Whole Home Tankless Water Heater
Eccotemp 45HI-LP Indoor Tankless Water Heater is NOT Recommended for a Closed-loop Installation.
Eccotemp 45HI-LP Indoor Tankless Water Heater is NOT Recommended for a Closed-loop Installation.
Updated over a week ago

Eccotemp got an email from a customer with a 45HI-Liquid Propane Tankless water heater. The customer installed it recently, and it is having problems. The water heater lights up and heats water as it should, but it keeps turning off after about 20-30 minutes of use, without showing any error codes.

Closed Loop Circulation.JPG

The provided image shows a 45HI-LP Indoor Tankless Water Heater. Arrow (1) points to connections for the closed-loop circulation system, and arrow (2) highlights the radiant floor heating connections. However, the 90-degree elbow indicated by arrow (3) lacks a downward slope, which might cause condensation to flow back into the water heater, potentially damaging it.

The 45HI Liquid Propane Indoor tankless water heater is not recommended for closed-loop circulation. For this particular tankless water heater, it is not designed to support this type of installation. The reasons are listed below.

  1. On the first pass-through, this water heater heats water to the desired set temperature. As the already heated water re-enters the water heater it will then not heat the water again. Why? Because this water heater has too high of a minimum BTU rating. Meaning, that the minimum temperature rise is too great which will overheat the water heater. The control board uses calculations based on incoming water temperatures to not allow the water heater to re-heat the water. This is for safety and to help avoid scalding water temperatures to be produced.

  2. Another reason is if the water flow is too low it may not even turn on. There is a minimum water flow activation programmed as well to help avoid producing scalding hot water.

  3. Radiant floors can use a mix of chemicals and water which will cause damage to this water heater. Using radiant floor solutions mixed with other chemicals such as Propylene Glycol will immediately void the manufacturer's warranty. The Eccotemp 45HI-LP and NG versions are not designed for this use.

How we fixed this water heater: We advised the customer not to use this product in a closed loop and to reinstall it properly. Once this was done the water heater worked as designed and intended. It is used to simply produce hot water for showering and sinks now with no issues.

We always recommend taking advantage of our Free Pre/Post Purchase Consultation call with one of our experts to better understand the uses, installation, and common mistakes made when installing one of our products. We also always recommend hiring a professional licensed installer to ensure your installation is correct and intended for the product you purchased.

Here at Eccotemp, we understand the importance of a successful installation, which is why we provide pre-sale and post-sale product consultations. Our team can offer guidance on essential aspects of tankless water heater installation, including sizing, venting, and safety considerations. We’re here to support you throughout the entire process.

To take advantage of our consultation services or to schedule a call with one of our experts, please visit our booking page. Investing in professional installation and seeking expert advice ensures that you get the most out of your tankless water heater and enjoy reliable, energy-efficient hot water for years to come. Click here to schedule your call with our team today!

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