Rental Property Re-heating Function Guide: How to Check, Utility Costs, and Repair Responsibilities
A detailed guide to the benefits and selection of rental properties with re-heating functions, their impact on electricity and gas bills, and who pays for repairs.
What is a Re-heating (Re-circulation Heating) Function?
A re-heating function is a feature of hot water systems that can reheat bathwater that has cooled down. When bathwater cools, you can reheat it without running new hot water, which saves water and gas. Once you fill the tub once, the whole family can enjoy a comfortable bath.
In rental properties, whether or not a re-heating function is available depends on the building's age and grade. Especially in properties over 20 years old or budget studio apartments for single renters, many lack this feature, making it an important point to check when searching for an apartment.
How to Check if a Property Has a Re-heating Function
Here are effective ways to check whether a property has a re-heating function during your search:
Checking Property Listings and Floor Plans
If you see terms like "re-heating," "auto bath," or "fully automatic" listed in the property's equipment list or floor plan notes on rental property websites, the feature is installed. If there's no mention, it likely doesn't have the feature, so be sure to confirm when inquiring.
Checking During a Property Viewing
Check the remote control panel in the bathroom. If you see a "re-heating" button or "keep warm" function displayed, it's installed. Also, if there are circulation ports (fittings with two holes) at the lower side of the tub, it's equipped for re-heating. If there are no circulation ports, you can assume the property doesn't have a re-heating function.
Contacting the Property Management Company
By asking the management company for "the brand and model number of the water heater," you can determine in advance whether the property has a re-heating function.
Types of Re-heating Functions
There are mainly the following types of re-heating functions:
Integrated Water Heater (Most Common)
The same water heater that supplies hot water to the kitchen and bathroom also heats the bathwater. Note that when using the shower at the same time, water pressure may decrease.
Fully Automatic Bath
Automatic water filling to a set temperature, keeping it warm, and re-heating all happen automatically. Many models announce when the tub is filled, offering high convenience.
Auto Bath
Automatic water filling is available, but keeping warm and re-heating require manual operation.
Re-heating Only (Manual)
You fill the tub manually, and re-heating is used only when the water cools down.
Gas and Electricity Costs for Re-heating
The utility costs for re-heating vary depending on the type of energy used and how often you use it.
With a Gas Water Heater
A single re-heating typically costs around 20-50 yen in gas (this varies depending on tub size and temperature difference). In most cases, re-heating is more gas-efficient than draining the entire tub and refilling it. However, if the remaining water is very cold or the tub is large, costs will be higher.
With Electric Water Heaters or Eco-cute Systems
There are electric water heating systems with re-heating capability as well. With eco-cute systems that use off-peak electricity rates, re-heating costs can be kept relatively low.
Money-Saving Tips
•Cover the tub immediately after bathing (the insulation effect slows temperature loss)
•Use an insulated tub cover
•Have family members bathe consecutively to maintain warmth
Who Pays for Repairs
Here's who pays for repairs when a water heater with re-heating function breaks down:
When the Management Company (Landlord) Pays
•Natural failure due to age (water heaters typically last 10-15 years)
•Manufacturing defects
•Water leaks from aging pipes
When the Tenant Pays
•Damage caused by tenant negligence or intentional acts (such as putting foreign objects in the tub)
•Clogging due to neglecting to clean the re-heating system's filter
Re-heating pipes tend to accumulate soap residue and mineral deposits, so regular cleaning is recommended. To clean, simply dissolve a store-bought "re-heating pipe cleaner" in the tub and run the re-heating function. Maintenance once or twice a month is recommended.
When the water heater breaks, always contact the property management company first. Avoid self-repairs or hiring your own contractor. If repaired by anyone other than the management company's designated service provider, you may have to pay all or part of the repair costs.
How to Keep Water Warm in Properties Without Re-heating Functions
Even without a re-heating function, you can keep bathwater warm longer with some clever tips.
•Thermal Bath Sheets: Floating insulated aluminum sheets cost around 500-2,000 yen and are effective at retaining heat
•Adding Hot Water: Add small amounts of hot water as it cools to maintain comfortable temperature
•Insulated Tub Covers: Replace your tub lid with an insulated version (if renting, check with your management company first)
•Shorter Bath Times: If the water cools quickly, switching to primarily shower-based bathing can reduce utility costs
A re-heating function is important equipment for comfortable bathing. While it's often overlooked when choosing a rental property, whether it has this feature directly affects your quality of life, especially during cold seasons. Be sure to check for it during your property viewing, and choose your apartment with long-term comfort in mind.
During apartment viewings, it's easy to focus on room size and natural lighting, but the condition of water fixtures actually has a major impact on your satisfaction after moving in. We'll explain specific inspection checkpoints for bathrooms, toilets, kitchens, and washbasins.
