The most frequently complained-about issues in OTA

Starting from the most frequent issues in OTA negative reviews—odors, air conditioning, hot water, noise, network, and elevators—this reverse-analyzes the closed-loop MEP systems in hotel development and operations.

The Most Complained-About Aspects on OTAs

After a hotel opens, the most authentic acceptance is often not the completion acceptance, nor the brand inspection, but the OTA review section.

Guests do not write reviews by discipline—HVAC, plumbing, electrical, fire protection, low-voltage, finishes. They only write: the room smells, the AC isn't cold, hot water is too slow, the bathroom smells, soundproofing is poor, the network lags, the elevator takes too long, there's noise at midnight, the room is damp, the shower water alternates hot and cold.

These words look like "customer experience issues," but in the eyes of hotel engineering experts, many OTA complaints correspond to systemic problems that were not properly resolved during the pre-opening phase. Truly professional hotel pre-opening is not about waiting for bad reviews to appear and then having the front desk apologize and the engineering department repair—it is about converting these high-frequency complaints in advance into checklists, test metrics, and closed-loop actions during the design, construction, commissioning, acceptance, and operations stages.

HotelM&E AI focuses on OTA complaints not to do public-opinion monitoring, but to reverse-identify the weaknesses of hotel MEP and operating systems. Because the OTA review section contains the most direct feedback on hotel engineering quality.

I. Why OTA Complaints Are Particularly Important for Hotel Projects

OTA complaints are not a few isolated bad reviews; they affect the hotel's conversion rate, average room rate, repeat-purchase rate, and brand trust.

This is especially pronounced in high-end hotels. Guests who pay a higher price have lower tolerance for basic experiences. Slow hot water, uncomfortable AC, smelly rooms, unstable networks, and long elevator waits may not prompt guests to complain strongly on the spot, but they will directly appear in reviews. OTA platform ratings and keywords affect whether future guests place orders, and also affect the hotel's ranking and reputation among competitors in the same area.

More critically, OTA complaints are often not single-point issues but external manifestations of system problems.

For example, "the room smells" may come from multiple systems: bathroom water seals, venting, exhaust, fresh air, decoration materials, damp carpet, AC condensate, and kitchen odor crossover; "the AC isn't cold" may come from the cooling source, chilled water, low temperature difference with high flow, dirty or blocked fan coil units, fresh air dehumidification, control panels, and guest room control strategies; "can't sleep" may come from soundproofing, but also from air outlet noise, water pump vibration, elevator shafts, exhaust fans, and pipe water hammer.

If OTA complaints are treated only as a front office or housekeeping issue, the hotel will be treating symptoms rather than root causes for a long time.

II. The Most Frequent Aspects of OTA Complaints

1. Hygiene and Odor: What Guests Are Most Sensitive To and Most Likely to Leave Bad Reviews About

In OTA reviews, "the room smells," "the bathroom smells," "sewer smell," "musty smell," "smoke smell," and "damp smell" are very high-frequency keywords.

On the surface, these issues are attributed to cleaning, but behind them are often engineering problems:

Floor drain water seal depth is insufficient or has dried out over time;
Drainage horizontal pipe slope is insufficient, causing sediment accumulation;
Vent pipes are missing or blocked, siphoning off the water seal during drainage;
Bathroom exhaust volume is insufficient, and negative pressure organization is wrong;
Fresh air volume is insufficient, and room air exchange is slow;
AC condensate pan has standing water, insulation condensation, and ceiling dampness;
Odors from the kitchen, garbage room, and linen room enter guest areas through shafts or corridors;
Decoration materials, carpet, and wood veneer release odors in humid environments.

High-end hotels should treat "no odor" as an engineering acceptance metric, rather than relying solely on housekeeping. During the mock-up room, mock-up floor, and soft-opening periods, bathroom odor tests, exhaust tests, AC condensate checks, fresh air volume checks, and air re-checks of low-occupancy rooms should be conducted.

2. AC Comfort: It's Not Just "Not Cold"

OTA complaints about AC are usually written very directly: the AC isn't cold, the AC is too cold, the temperature can't be adjusted, the room is stuffy, humid, musty, or noisy.

Behind these issues may be multiple disciplines:

Insufficient cooling capacity of chillers and chilled water systems;
Low chilled water supply-return temperature difference, resulting in low temperature difference with high flow;
Water volume imbalance in terminal fan coil units, with far-end rooms not cooling;
Two-way valves failing open or closed;
Insufficient fresh air dehumidification capacity, with high humidity while temperature appears to meet standards;
Unreasonable air outlet locations, short-circuiting of supply and return air, or direct blowing onto the head of the bed;
Confusing guest room control panel logic, making guest adjustments ineffective;
Dirty or blocked filters and poor condensate drainage, causing musty odors and noise.

Hotel AC acceptance cannot just check "the main unit starts and the room has airflow." What really needs to be checked is temperature, humidity, noise, airflow sensation, dehumidification, control response, and the guest's actual sleep experience. Especially in southern, island, and plum rain season regions, humidity control is often more likely to trigger bad reviews than temperature.

3. Hot Water Experience: Waiting Time and Stability Determine Bathing Reviews

"Hot water takes forever," "the water alternates hot and cold," "the water pressure is low," and "bathing is uncomfortable" are also high-frequency OTA complaints.

Hot water problems are most easily misdiagnosed as boiler or heat pump problems, but the real root cause in many hotels lies in the circulation system:

Far-end branch pipes have no effective circulation;
Hydraulic imbalance in return water branches;
Unreasonable circulation pump control strategies;
Damaged insulation causing heat loss;
Poor venting at high points;
BMS only looks at machine room temperature, not floor and terminal temperatures;
Mixing valves, showerheads, and faucet filter screens are blocked;
Peak water usage model does not match actual occupancy.

For high-end hotels, hot water acceptance cannot just check temperature in the machine room. It is necessary to sample-test far-end rooms, end rooms, suites, and high-zone rooms, recording the waiting time to reach usable temperature, water pressure, water temperature stability, and continuous test results.

4. Noise and Sleep: The Hidden Issue Most Likely to Affect Ratings

Guests have very low tolerance for noise, especially at night. Common OTA comments include: poor soundproofing, loud AC, noisy corridors, noisy elevators, upstairs drainage noise, pipe noise, equipment vibration noise, and kitchen fan noise.

Noise sources are usually not just decoration soundproofing issues; they also include:

Inadequate vibration isolation in fan coil unit selection and installation;
Excessive air outlet velocity, generating airflow noise;
Vibration from water pumps, fans, and cooling towers transmitted through the structure;
Pipe water hammer and drainage riser noise;
Elevator shafts adjacent to guest rooms, with insufficient vibration and sound isolation;
Improper interface treatment between back-of-house kitchens, laundry rooms, and equipment rooms and guest areas;
Noise from banquet halls, bars, and machine rooms transmitted to guest rooms.

During the hotel pre-opening stage, a dedicated noise review must be conducted. Guest rooms, corridors, equipment rooms, kitchens, banquet halls, elevator shafts, and rooftop equipment platforms must all consider nighttime conditions and structural sound transmission, rather than only testing during the daytime in empty conditions.

5. Network and Smart Systems: Guests Don't Care About the System, Only Whether It Works Well

In OTA reviews today, network issues are increasingly common: slow WiFi, poor signal, screen casting failure, TV lag, door lock malfunction, unusable lighting scenes, and unusable AC panels.

If smart hotels only pursue "many functions" without properly executing low-voltage network and system integration commissioning, they will instead increase complaints:

Guest room AP locations are unreasonable, with weak signals in bathrooms or at headboards;
Guest network, device network, door lock network, and GRMS network are chaotic;
IPTV, screen casting, PMS, and GRMS interfaces are unstable;
GRMS scene logic does not match guest habits;
Door locks offline, elevator access control abnormal, curtain linkage failing;
Insufficient UPS backup in the weak-current equipment room; short power outages affect system recovery.

Acceptance of intelligent systems should not rely only on demo functions; it must include occupied-room scenario testing: check-in, door opening, card insertion or cardless power activation, lighting, curtains, air conditioning, TV, WiFi, checkout cleaning, and engineering maintenance—full-process linkage.

6. Elevators and Circulation: Long Waits, Congestion, and Back-of-House Crossings All Become Negative Reviews

Elevator complaints are also common in hotel OTA reviews: long waits for elevators, slow elevators, sharing rides with linen carts, congestion during banquet peaks, and poor access from the parking lot to the lobby.

On the surface, these issues appear to be operational organization, but in the early stage they are related to architectural and MEP planning:

The number of guest elevators does not match the number of guest rooms and meeting/banquet traffic;
Insufficient service elevators, with linen, F&B, garbage, and engineering maintenance occupying guest elevators;
Unclear functional boundaries among fire elevators, service elevators, and freight elevators;
Elevator access control strategies do not match guest room, banquet, and parking lot circulation;
Elevator group control is not optimized during peak periods;
Back-of-house corridors and guest circulation cross each other.

The elevator system in a high-end hotel is not only an equipment issue, but also an issue of guest flow experience and operational efficiency. During the pre-opening stage, circulation must be reviewed in combination with business formats and peak scenarios.

III. The Real Root Cause: OTA Negative Reviews Are Often Not a Single-Department Issue

OTA complaints are most easily attributed simplistically: poor hygiene to the housekeeping department, slow service to the front office, facility problems to the engineering department. This attribution approach causes hotels to repeat fixes over the long term.

The real root causes are usually cross-discipline, cross-stage, and cross-department:

The design stage does not translate guest experience into engineering indicators;
The construction stage leaves no evidence for concealed problems;
The commissioning stage only tests individual equipment, not occupied-room scenarios;
The acceptance stage only looks at the minimum code requirements, not hotel operating standards;
The opening stage lacks sufficient trial stays and issue closeout;
The operation stage does not correlate guest complaints with engineering data;
Management only looks at rating results and does not trace back to system defects.

Therefore, reducing OTA complaints is not about making the front desk better at explaining, nor about making the engineering department repair faster, but about establishing an "experience—engineering—data—closed loop" management system from the pre-opening stage.

IV. Expert Consultation Checklist: Tracing Engineering Systems from OTA Complaints

HotelM&E AI recommends that hotels establish an OTA complaint engineering consultation mechanism. Each type of high-frequency complaint should correspond to a set of professional checklists.

Odor complaints: Check floor drain water seals, drainage venting, bathroom exhaust, fresh air volume, air-conditioning condensate, and odor migration paths from garbage rooms and kitchens.

Air-conditioning complaints: Check room temperature and humidity, diffuser air velocity, noise, fan coil water flow, filters, condensate, GRMS logic, and BMS curves.

Hot water complaints: Check terminal waiting time, supply and return water temperatures, circulation pump frequency, balancing valve opening, insulation, venting, and remote branch pipes.

Noise complaints: Check fan coils, diffusers, drainage risers, water pumps and fans, elevator shafts, equipment rooms, back-of-house machine rooms, and nighttime operating conditions.

Network complaints: Check AP signal coverage, bandwidth, roaming, guest network isolation, device network stability, weak-current equipment room UPS, gateways, and account permissions.

Elevator complaints: Check waiting time, group control strategy, peak passenger flow, service elevator configuration, back-of-house circulation, elevator maintenance records, and fault trends.

Hygiene complaints: In addition to cleaning, also check ventilation, humidity, leakage, mold, drainage, condensate, and material contamination sources.

V. Key Judgment Indicators

OTA complaint management should shift from subjective evaluation to quantifiable indicators. At minimum, the following indicators are recommended:

Number of engineering complaints per 100 room nights;
Frequency of OTA negative review keywords;
Repeat rate of odor room numbers;
Measured temperature and humidity in rooms with air-conditioning complaints;
Waiting time for hot water to reach usable temperature;
Measured nighttime noise in guest rooms;
WiFi signal strength and speed test results;
Average elevator waiting time during peak periods;
Number of repeated repairs for the same room number;
Recurrence rate after complaint closure;
Average time from discovery to closure of engineering issues;
Whether complaints generate root cause analysis and rectification records.

High-end hotels should not only look at "how many complaints were handled today," but at "why similar complaints recur."

VI. Rectification Path: From Firefighting Repairs to a Systematic Closed Loop

Step 1: Complaint Classification

Unify the classification of OTA reviews, front desk complaints, housekeeping work orders, and engineering repair orders, distinguishing types such as hygiene, service, engineering, noise, air conditioning, hot water, network, elevators, and odor.

Step 2: Room Number and System Correlation

Each complaint must be linked to room number, floor, system zone, occurrence time, occupancy rate, weather, and equipment operating status. For example, air-conditioning complaints should be linked to chiller plant and terminal data, hot water complaints to return water temperature, and odor complaints to drainage and exhaust systems.

Step 3: Expert Consultation

For recurring complaints, no longer handle them as individual work orders; instead, organize cross-discipline consultations. Plumbing, HVAC, weak-current systems, finishes, operations, housekeeping, and front office jointly determine the root cause.

Step 4: Rectification Verification

After rectification, it is not enough to reply "handled"; retesting is mandatory. Hot water requires waiting time testing, air conditioning requires temperature and humidity measurement, odor requires rechecking exhaust and water seals, noise requires nighttime retesting, and network requires speed and roaming tests.

Step 5: Review and Documentation

Conduct a monthly review of OTA complaint keywords to form a problem ranking, responsible systems, rectification status, and investment recommendations. For issues requiring capital improvements, form budgets and return calculations.

VII. How HotelM&E AI Intervenes

HotelM&E AI can transform OTA complaints from "emotional negative reviews" into "engineering diagnostic clues."

It can help hotels accomplish several things:

1. Automatically extract OTA negative review keywords
Identify high-frequency words such as air conditioning, hot water, odor, noise, network, elevators, and hygiene from reviews, and classify them by room number, time, and system.

2. Generate engineering consultation checklists
Automatically generate check items for each type of complaint, e.g., hot water complaints correspond to the circulation system, odor complaints to drainage and ventilation, and network complaints to weak-current coverage and isolation.

3. Correlate BMS and operational data
Link complaint occurrence times with temperature and humidity, return water temperature, pump frequency, equipment alarms, elevator operation, and network status to help the engineering department locate issues quickly.

4. Output rectification closed-loop reports
For each high-frequency issue, form cause analysis, rectification measures, responsible persons, completion time, retest results, and recurrence monitoring.

5. Create a pre-opening reverse checklist
Convert high-frequency OTA complaints into an acceptance checklist for the pre-construction phase, so that new hotels can check the systems most likely to be criticized by guests—hot water, air conditioning, odors, network, noise, and elevators—before opening.

VIII. Suggested Illustrations

1. OTA complaint keyword heatmap
The horizontal axis is complaint type, and the vertical axis is frequency, highlighting high-frequency issues such as odors, air conditioning, hot water, noise, network, and elevators.

2. Mapping diagram from OTA complaints to engineering systems
Map "the room smells" to drainage, ventilation, fresh air, condensate water, and decoration materials; map "the air conditioning is not cold" to cooling sources, terminal units, guest room control, and BMS.

3. Complaint closed-loop flowchart
OTA review → keyword identification → room number localization → system data correlation → expert consultation → rectification → retest → review.

4. Distribution map of high-frequency complaint room numbers
Mark repeatedly complained-about rooms on a floor plan to help identify problems in a certain riser, a certain area, or a certain equipment system.

5. Sample pre-opening OTA risk pre-check form
Includes check items such as hot water waiting time, air-conditioning temperature and humidity, odors, noise, WiFi, elevators, and hygiene blind spots.

Closing Remarks

The aspects most frequently complained about in OTA reviews appear on the surface to be hygiene, air conditioning, hot water, odors, noise, network, and elevators, but behind them are actually the combined results of a hotel's pre-construction and operational systems.

A truly professional hotel should not wait for guests to tell it in the review section where the problems are. It should know during the pre-construction phase: which problems are most likely to be complained about, which systems are most likely to affect the experience, which indicators must be tested in advance, and which data must be monitored over the long term.

The value of HotelM&E AI is to turn the high-frequency negative reviews in OTA review sections into an expert checklist for hotel pre-construction and operations in advance. Let hotels explain less and prevent more; rework less and close the loop more; have fewer negative reviews and more truly stable guest stays.

Engineering reference only — verify against project conditions and the latest codes.