The Rinnai RU199iN Condensing Tankless Hot Water Heater doesn't have a built-in recirculating pump. If you're aiming to cut down on the wait time for hot water, you can pair it with an external pump, thanks to its compatibility and the Circ-Logic feature that lets you schedule or demand hot water recirculation. This can be particularly useful if your home's plumbing layout means long waits for hot water.

From our research, experiences with an external pump do vary. Some folks find it really convenient, enjoying quicker hot water delivery. A few have even used a pump from their old tank heater with success. However, if quick hot water is a big priority for you, Rinnai's RUR series might be worth a look since it has a built-in pump.

Despite missing a built-in pump, the RU199iN is pretty efficient, especially with its high GPM flow rate. If your home's faucets are far from the heater, adding an external pump could be useful for quicker hot water access.

Just keep in mind, getting a pro to handle the installation is a smart move to avoid hiccups and ensure everything runs smoothly.

So, while the RU199iN doesn't have a built-in pump, it's still a solid option for many homes. Think about your plumbing setup and hot water needs to decide if an external pump is necessary.

Hope this helps with your decision on how to get efficient hot water delivery in your place!

The Rinnai RU199iN tankless water heater can heat water up to 140°F (60°C), which is typical for most residential needs like showers, dishwashing, and laundry, according to our research.

This heater is designed for indoor installation and provides efficient and consistent hot water. However, it doesn't have a built-in recirculating pump. This could mean longer waits for hot water, especially if your home is larger, because the water in the pipes might cool off. When you first turn on the tap, you might get a burst of cold water at fixtures that are far from the unit.

If quick access to hot water is important, you can pair this unit with Rinnai's ThermaCirc360 technology. Though you'll need an external recirculation pump for that, it keeps warm water circulating, cutting down on the cold water delay.

If you're looking for a heater with a built-in recirculation system, Rinnai’s RUR series might be worth checking out. These models have integrated recirculation pumps, which can make getting hot water faster and can save you some installation work.

The Rinnai RU199iN is a solid choice for efficient water heating, but think about how fast you want your hot water and consider options like the RUR series if you need a built-in recirculation system.

If you're wondering how quickly the Rinnai RU199iN heats water, here's what to know. This tankless water heater can provide up to 11 gallons per minute (GPM) according to the manufacturer's product description. So, it's pretty efficient at running multiple appliances with hot water without a noticeable drop in temperature, even if the incoming water is on the colder side.

The unit packs quite a punch with a 199,000 BTU input capacity, allowing it to heat water fast to your desired temperature. Plus, it includes Rinnai's ThermaCirc360 technology, which is great for cutting down on wait time by recirculating warm water through your plumbing lines. This means you almost have instant hot water, which is a win, especially in colder areas.

Generally, our research suggests that this model is efficient, though you might notice a brief delay initially when heating water, especially in bigger homes or setups without a recirculation pump. It takes a bit for the unit to kick in and adjust when the incoming water is super cold.

But once it's up and running, it should consistently deliver hot water without issues. To get the best performance, make sure it's installed correctly and has the necessary gas supply.

With everything set up properly, the Rinnai RU199iN should give you a steady supply of hot water, even when it's freezing outside.