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Approval Required for Installation of Electronic Toilet Seats to Avoid Backflow of Contaminated Water into Freshwater Pipes Enjoy Abundant Functions While Paying Heed to Temperature and Hygiene to Avoid Skin Damage

  • 2022.11.15

A warm toilet seat will no doubt increase comfort during use. This was why electronic toilet seats, which combine the functions of seat heating and water spray cleansing, have become increasingly popular among consumers in Hong Kong in recent years. With the increased variety of models available in the local market, the Consumer Council has collected information on 32 electronic toilet seat models to help consumers understand the functions of relevant models such as seat heating, warm water cleansing and self-cleaning nozzles, etc. The Council reminds consumers that while electronic toilet seats may seem convenient, they should not be taken lightly in terms of installation, usage and hygiene. As the installation of electronic toilet seats requires connection to a freshwater supply pipe, written permission from the Water Supplies Department (WSD) and installation by a qualified professional are required to avoid backflow of contaminated water and subsequent contamination of the water supply system of the flat or building. In addition, as some models can reach a maximum seat temperature of 40˚C, consumers are advised not to set the temperature too high or sit for too long to avoid skin discomfort. Besides, users should also pay heed to the daily cleaning and maintenance of electronic toilet seats and follow the instructions in the manual for regular cleaning of the body and nozzle to ensure hygiene. Furthermore, although some models claimed that their massage cleansing function could stimulate the posterior to help to defecate, the Council reminds consumers if they suffer from chronic constipation, they should seek medical advice for proper treatment.

Electronic toilet seats are mainly sold in sanitary ware shops, electrical appliance stores and online shops. The Council collected information on 32 models from 9 brands, priced from $3,399 to $14,800, a difference of more than 3 times, with the basic installation fee included for some models. As the water filters or deodorising filters in some models require regular replacement, consumers are advised to consider the cost of replacing all filters when purchasing.

Installation: WSD Written Permission and Set-up by Qualified Professionals Required

Electronic toilet seats possess seat heating, cleansing and even massage functions. However, consumers should note that all electronic toilet seats must be connected to a power supply and a freshwater supply pipe when in use. A break tank or equivalent backflow prevention device is required to prevent the backflow of contaminated water from contaminating the water supply system of a flat or building. The break tank should supply water to the electronic toilet seat only, while it can be built into the electronic toilet seat or installed at the water supply pipe which supplies water to the electronic toilet seat. Moreover, the works must be carried out with the written permission of the WSD under the Waterworks Ordinance and by designated persons such as licensed plumbers or registered plumbing workers. For connections to the power supply, as bathrooms are usually more humid, the use of extension units should be avoided. If additional socket outlets are required, they must be installed by registered electrical contractors and should be located 0.6m away from shower basins or bathtubs to avoid damage caused by water splashes. Consumers should also ensure that the rated voltage and frequency of the product are suitable for local use and the products are fitted with plugs[1] complying with the safety requirements.

Temperature of Seat and Warm Air Dryer, Water Spraying Speed Require Fine Adjustments

Once the electronic toilet seat has been installed properly, it is important to stay mindful during everyday use. All 32 models surveyed had a seat heating function with adjustable temperature. 12 of the models claimed to be able to adjust the seat temperature to a maximum of approximately 40˚C, while 2 models had the widest adjustment range from approximately 28˚C to 40˚C. The Council advises users to neither set the seat temperature too high nor sit for too long as one might not feel hot in the first place, but when the heat accumulates over time, the temperature might increase causing the user to feel hot. Even if the seat temperature is only slightly higher than the body temperature, it may still cause discomfort with prolonged contact with the skin. 24 models claimed that the temperature would be automatically lowered after users had been sitting on the seat for a period of time to reduce the chance of skin discomfort due to prolonged skin contact with higher temperatures.

There is literally a price to pay to enjoy a warm, toasty seat. According to rough estimates provided by some suppliers for individual models, the monthly power consumption is around 10 to 13 units of electricity to maintain the seat at a temperature of approximately 36˚C to 39˚C at a room temperature environment of roughly 20˚C to 24˚C. The actual power consumption is affected by many factors, such as the room temperature, product performance, seat temperature setting and the habit of closing the toilet seat cover after use to reduce heat loss, etc. 30 models offered a power-saving mode which would pause the seat heating function or lower the seat temperature to save power.

Some consumers choose to install electronic toilet seats not only because of their seat-heating capability but also because of their water spray cleansing function. As the elderly and disabled people with limited mobility may find it difficult to clean their lower body parts after using the bathroom, some electronic toilet seats claimed that their cleansing function could bring convenience to these people and help relieve the unpleasant cleaning task for carers.

All 32 models had posterior and feminine cleansing functions, with adjustable warm water temperature and forward and backward extension of the nozzle, as well as an oscillating cleansing function to cover a wider area with automatic forward and backward extension of the nozzle while spraying water. In addition, all models allowed adjustment of the speed of the water sprays. Out of the 24 models that provided the Council with information on the speed of the spraying stream, the highest claimed speed was approximately 700ml/minute at the maximum setting, applicable to 9 models of the same brand. The Council reminds users that, regardless of the models, it is advisable to adjust the water spraying rate to a lower band when using for the first time and increase the water spraying rate as necessary. 3 surveyed models had a child cleansing mode. As children’s skin is more delicate, the spraying speed and warm water temperature should be set to a lower band. Furthermore, 30 models were equipped with a massage cleansing function, where the speed of the spraying stream would automatically vary to create a massage effect. Some models claimed that this function could stimulate the posterior to increase the urge to defecate. However, the Council reminds consumers to seek medical advice in case of chronic constipation.

29 models were equipped with a warm air dryer function, allowing users to dry their lower body parts with warm air after cleansing. 8 out of the 25 models that provided the Council with information on the warm air temperature claimed the warm air temperature could be adjusted to a maximum of approximately 60˚C, which despite being lower than the 65˚C upper limit of the recommended Guobiao standard, might still cause skin discomfort when prolonged use. In Japan, a consumer had reported to the local consumer organisation on being scalded by the warm air of an electronic toilet seat. The Council reminds consumers not to turn up the dryers’ temperatures too high but to wipe the lower body parts with toilet paper after cleansing before drying with warm air to reduce skin discomfort that may be caused by prolonged exposure to warm air at higher temperatures.

Cleaning: Clean Nozzles and Replace Filters Regularly to Ensure Hygiene

When using the cleansing function after toileting, the nozzle will inevitably be splashed with contaminated water. Although all models were equipped with a self-cleaning nozzle function which claimed to automatically clean the nozzle with water before and/or after each cleansing, consumers are still required to clean the nozzle regularly with a soft cloth or sponge as instructed in the manual to ensure its hygiene. 16 models allowed consumers to remove the nozzle casing to clean the dirt inside and outside the nozzle. 30 models allowed users to remove and reinstall the entire electronic toilet seat without using tools, such as a screwdriver, for more thorough cleaning.

All models had a built-in or attached water filter, which filters the water before it is ejected through the nozzle. 11 models required regular replacement of the water filters, at a frequency of once every 4 months to 1 year as recommended by the manufacturers. The filters were priced from $75 to $400 each. In addition, the deodorising filters of 6 models required regular replacement. The relevant manufacturer suggested the filters be replaced when users noticed a decline in the deodorising performance, while each deodorising filter cost $380. Consumers should also consider the cost of filter replacements when purchasing electronic toilet seats.

If the home environment is suitable for the installation of electronic toilet seats, it may bring more comfort and convenience to daily living, but consumers should pay heed to the following points for installation, usage and maintenance:

  • There are 2 types of warm water supply mechanisms, namely instantaneous and storage types. The instantaneous type generally provides a continuous stream of warm water over a long period of time. On the other hand, the storage type requires pre-heating of water, and hence the output water temperature will drop after a period of continuous use. Warm water can only be resumed after the water in the storage tank has been reheated. Therefore, within the same brand, the storage-type models are usually cheaper than the instantaneous-type models;
  • If the toilet is located close to the bathtub or shower, consumers are advised to use a shower screen or curtain to avoid splashing water on the electronic toilet seat;
  • Individuals with lower body discomfort or wounds, such as haemorrhoids, are advised to consult the doctor before use;
  • Unplug when not in use for a prolonged period and drain the water from the machine according to the instructions in the manual to prevent the water from deteriorating and causing skin discomfort when in use again.

[1] Consumers should choose products with a rated voltage and frequency suitable for use in Hong Kong (220 Volts (V), 50 Hertz (Hz) Alternating Current (AC)) and which are fitted with plugs complying with safety requirements.



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