Pratt Plumbing Explains How To Deal With A Delay In Hot Water From A Tankless Water Heaters

Tankless water heaters have earned a range of nicknames, including on-demand water heaters and instant water heaters. These nicknames are accurate when they understand how tankless systems work compared to standard tank water heaters. But the reality is that the hot water isn’t literally ‘instant.’

With tankless water heaters, there can be a short delay as hot water must travel from the heater to the open outlet. If this is a major concern, a homeowner can try a few methods such as installing a water recirculation system or a secondary water heater close to the affected faucet.

Tankless water heaters

How a tankless water heater works – and why might there be a delay? Tankless water heaters use a powerful burner (for natural gas) or heating element (for electric) to quickly heat water as it passes through the unit. That means the water heater doesn’t have to store large amounts of hot water around the clock like a tank unit.

Hot water exits the tankless water heater and flows through pipes until it reaches an open outlet such as a faucet, showerhead, or appliance. Once that outlet is closed, the flow of the hot water line stops. Eventually, the water in the pipe will cool off, so when the outlet is opened next, they may get a short burst of cold water before the newly heated water has time to travel through the plumbing.

Secondary water heater

A recirculation system makes sure that unused hot water doesn’t sit in pipes to get cold

The length of the delay can be determined by a few factors, including the distance between the water heater and the outlet. In other words, the longer the water has to travel, the more cold water will need to be discharged before the hot water appears.

In most cases, this delay is no more than a few seconds, but if it’s longer or more than a minor inconvenience, there are ways to reduce the delay of a tankless water heater. 

Recirculation system – A recirculation system makes sure that unused hot water doesn’t sit in pipes to get cold. Instead, the system creates a loop between the water heater and the outlet. So when users turn on the faucet, the hot water waiting in the pipe is already warm. The downsides to recirculation systems are that they use extra energy and put more strain on the tankless system. But if having quicker hot water is important to them, a recirculation system is worth it.

Primary tankless water heater

Secondary water heater – Also known as a point-of-use water heater, this is a small unit that is installed right to the sink, shower, or another outlet. The idea is that a secondary water heater can heat any cold water left in the pipe, so it complements the primary tankless water heater. This type of water heater generally uses electricity and comes in tank or tankless models.

If users are concerned or frustrated about the delay of hot water coming from the tankless water heater, contact the professional team at Pratt Plumbing. They will determine what is causing the delay and recommend viable and affordable solutions.