[Survey Report] About 30% of EcoCute Replacements Regret "Should Have Replaced Sooner" | Most Replacements Occur at 10-13 Years of Use, 84% of Malfunctions Had "Warning Signs"

ARM System Co., Ltd. (Kawaguchi City, Saitama Prefecture, Representative Director: Shoki Kobayashi), which operates the specialized EcoCute replacement service "Koukan Paradise," conducted a survey on "Years of Use at Replacement," "Malfunction Warning Signs," and "Replacement Timing" targeting 200 men and women nationwide who have actually replaced their EcoCute units (May 2026 Internet Survey *Self-conducted).

The survey results showed that the most common replacement period was "10-13 years" of use (41.5%). Among the approximately 30% who responded "should have replaced sooner," about 60% cited "the 10th year" as their ideal replacement timing.

Based on the survey results, we will explain the appropriate replacement目安 for EcoCute and the malfunction warning signs that are often overlooked.

Top Reason for Replacement is "Frequent Errors" | Malfunctions Concentrate Around 10 Years of Use

The survey found that the main reason for replacement was "frequent errors" at 42.5%, making it the most common cause. Combined with "complete malfunction" (21.0%), over 60% decided to replace their unit due to a malfunction.

Regarding years of use, "10-13 years" was the most frequent at 41.5%. When combined with "8-10 years" (17.0%) and "13-15 years" (18.0%), those who replaced their units between 8 and 15 years accounted for 76.5% of the total.

Years of Use

Number of Responses

Percentage

Less than 5 years

5

2.5%

5-8 years

24

12.0%

8-10 years

34

17.0%

10-13 years (Most common)

83

41.5%

13-15 years

36

18.0%

15 years or more

18

9.0%

*For those who have already replaced, this is the number of years the previous EcoCute was used (n=200, self-conducted).

"Warning Signs" Before Malfunction. Pay Attention to Error Codes and Changes in Hot Water Temperature

As many as 84% of respondents reported having some kind of warning sign before a malfunction or defect occurred. The main warning signs cited were as follows:

Warning Signs Before Malfunction (Multiple Answers)

Response Percentage

Error code displayed

48.5%

Hot water temperature was unstable

36.5%

Hot water flow decreased

24.0%

Unusual noise occurred

10.0%

*Multiple answers allowed (n=200, self-conducted).

Display of error codes and changes in hot water temperature or volume may be signs to consider replacement.

The most common period from noticing a problem to deciding on replacement was "within 1 month" at 44.0%. Consulting a specialized contractor promptly when a warning sign is noticed can help minimize the impact on daily life.

About 30% Responded "Should Have Replaced Sooner." Ideal Timing is "the 10th Year"

Regarding replacement timing, 28.5% of respondents answered, "should have replaced sooner." Among these, the most common ideal replacement timing cited was "the 10th year" at 59.7%.

Evaluation of Replacement Timing

Percentage

Yes, it was just right

40.5%

Should have replaced sooner

28.5%

Cannot say either way

15.5%

Could have continued using it a little longer

15.5%

The general standard design life for EcoCute is approximately 10-15 years (*referencing publicly available data from various manufacturers). Therefore, considering an inspection or replacement around the 10-year mark is considered effective in preventing disruption to daily life due to sudden malfunctions.

For EcoCute Replacement, Choose "Koukan Paradise"

Koukan Paradise is a specialized EcoCute replacement service operated by ARM System Co., Ltd., a reform and construction company.

Specialized staff, including architects and electrical engineers, provide comprehensive support from inquiry and estimation to installation, subsidy applications, and after-sales support.

Strengths

Details

Google Reviews

Group total ★4.9 or higher / Over approx. 600 reviews (including related services)

Shortest Construction Period

Replacement possible as soon as the same day

Work Warranty

10 years free

Product Warranty

Up to 10 years free (*conditions apply)

Subsidy Application Support

- We handle applications for the "Kyuto Sho-ene Jigyō" (Hot Water Energy Saving Project).

- Customers are responsible for applying for other subsidies offered by prefectures or municipalities.

Service Area

Kanto region (entire), Chubu region (part), Chugoku region (entire), Shikoku region (entire)

If your EcoCute is around 10 years old or you are seeing error codes, please feel free to contact us.

Click here for details on "Koukan Paradise," which offers same-day installation in some cases.

▶ Koukan Paradise Official Website (https://reform-para.co.jp/ecocute/)

Survey Overview

Item

Details

Survey Name

Survey on EcoCute Replacement Standards and Lifespan

Survey Target

200 men and women nationwide who have experience replacing an EcoCute

Survey Method

Internet-based questionnaire survey

Survey Period

Early May 2026

Implementing Body

ARM System Co., Ltd. (Self-conducted)

Company Profile

Item

Details

Company Name

ARM System Co., Ltd.

Representative Director

Shoki Kobayashi

Established

February 2016

Location

597-3 Angyo Kitaya, Kawaguchi City, Saitama Prefecture, 334-0054

TEL

048-485-1714

Business Activities

General renovations, electrical equipment work, sales and installation of housing equipment

Official Website

https://armsystem.net/

EcoCute Service Site

https://reform-para.co.jp/

[Inquiries Regarding This Matter]

ARM System Co., Ltd. Koukan Paradise EcoCute Replacement Desk

TEL: 048-485-1714 Public Relations Representative

EcoCute Replacement Inquiry Form (https://reform-para.co.jp/ecocute/)