An annual maintenance contract ties the maintenance and fault response of air conditioning equipment to a single company for one year under specific rules. A well-written contract makes the facility manager's job easier; a badly written one turns into an argument of "this is not covered" at the first serious fault.
The most common problem we see in the field is a contract that amounts to nothing more than a one-page price quote. The checklist below shows, in order, the items your contract should contain before you sign.
Why is the equipment inventory the foundation of the contract?
The equipment inventory is an appendix listing every unit covered by the contract with its brand, model, capacity, serial number, location and refrigerant type. In a contract without an inventory, which units are covered stays unclear.
The inventory should list every unit, from split air conditioners to chillers, on a separate line. For VRF systems, the number of outdoor and indoor units should be written separately; for chillers and air handling units, pumps, valves and control panels should also be specified. The inventory is verified on site at the first visit and updated every year.
Also have the age of the units and their known chronic faults added to the inventory. This information shows from the start which units need spare parts in stock.
How is visit frequency determined by unit type?
Visit frequency should be set according to the unit type, operating hours and criticality; applying the same schedule to all units is not right. The maintenance needs of a split air conditioner in an office and a server room air conditioner running around the clock are different.
| Device | General maintenance frequency | Note |
|---|---|---|
| Split and cassette air conditioners | Twice a year | Before the cooling and heating seasons |
| VRF systems | 2–4 times a year | Depending on how heavily it is used |
| Chiller | Quarterly or monthly checks | Winter preparation as a separate visit |
| Air handling unit and fan coil | 2–4 times a year | Filter changes more often depending on the environment |
| Precision air conditioning | Monthly or quarterly | Alarm monitoring in critical areas |
These intervals are a general starting point. They should be written into the contract per unit, based on the manufacturer's maintenance instructions and the facility's operating conditions.
It also helps to put visit dates on the calendar at the beginning of the year. Scheduling pre-cooling-season maintenance for April–May and pre-heating-season maintenance for September–October reduces the risk of units failing during the busy period. For units in dusty areas, near kitchens or in production areas, interim visits should be added for filter checks.
What work should be done at every visit?
It is not enough for the contract to say "periodic maintenance will be carried out"; the work to be done for each unit type should be written out item by item. This list is the only way to verify that maintenance is actually performed.
- Filter cleaning or replacement
- Indoor and outdoor unit coil cleaning
- Drain pan and drain line check
- Suction and discharge pressure, superheat and subcooling measurement
- Compressor and fan motor current measurement
- Tightness check of electrical connections
- Belt, bearing and vibration check (air handling unit, rooftop)
- Water inlet and outlet temperature and flow check (chiller, fan coil)
- Reading and recording the alarm history
A maintenance visit carried out without measurements often amounts to nothing more than cleaning the filter. If the contract clearly states which values will be measured, this risk disappears.
Why should the fault response time be written down?
The response time is the maximum time from the fault report until the technician reaches the site, and it should be written in the contract in hours. A phrase such as "as soon as possible" cannot be measured, and therefore cannot be checked.
It makes sense to set different times for critical and non-critical faults. For example, a few hours may be reasonable for a server room or operating room air conditioner, and the next business day for an office air conditioner. How response will be handled outside working hours, on weekends and on public holidays, and whether there is an extra charge, should also be written down.
The resolution time is as important as the response time. Even if the technician arrives on time, getting the parts can take weeks. For this reason, the obligation to provide a temporary solution, such as supplying a standby unit in a critical area or running the system at partial capacity, should be defined separately in the contract.
Let's prepare your contract together
We will see your equipment on site and present a draft contract covering the inventory, maintenance schedule and response time.
A single phone number, e-mail address and report form should be designated for fault reports. Giving every report a ticket number allows the response time to be verified later.
Are parts, refrigerant and consumables included?
What the contract price covers is the biggest source of disputes that arise later. For this reason, labor, consumables, spare parts and refrigerant should be addressed separately.
- Consumables: It should state whether items such as filters, belts and cleaning chemicals are included.
- Spare parts: If parts are excluded, a unit price list or discount rate valid for the duration of the contract should be attached.
- Refrigerant: It should specify how refrigerant charging will be priced per kilogram and whether leak detection is within the scope.
- Major repairs: It should be clearly stated that work such as compressor replacement will be done under a separate quote.
What should reporting and record keeping look like?
At the end of each maintenance visit, a written report should be delivered containing, per unit, the measured values, the work done, the problems found and recommendations. The report is the proof of maintenance and the comparison point for the next visit.
It is important to keep the reports in the same format over the years. A slow rise in compressor current or a drift in pressures can only be noticed this way. We explain why this matters in detail in our article on chiller compressor failure symptoms.
The report should also include the leak check records that must be kept under F-gas legislation. For units whose refrigerant quantity is above certain thresholds, these records are a legal obligation.
It is also useful to ask for a summary report at the end of the year. This report includes the total number of faults, the units that failed most often, the parts replaced and renewal recommendations for next year. Budget planning is much healthier when based on this summary.
Final checks before signing
Before signing the contract, check the company's authorization and certificates, its insurance and the certifications of its technicians. We list the questions you should ask in our article 8 questions to ask when choosing a technical service.
The contract term, price adjustment condition, termination terms and contact persons should also be written down. In public institutions these items are in the technical specification; in the private sector they should be attached to the contract.
At YOİ Mühendislik, our annual maintenance contracts include the inventory, a per-unit work list, a written response time and a report with measurements as standard. The scope and price are determined at the first site survey, after the units are seen on site.
Frequently asked questions
What is the difference between an annual maintenance contract and a one-time maintenance visit?
With a one-time maintenance visit, only that visit is performed. An annual contract includes scheduled visits, prioritized fault response within a written time frame, contract pricing for parts, and measurement records that can be compared over the years.
Should spare parts be included in the contract?
Both approaches are possible. Contracts that include parts fix the budget but cost more; in contracts that exclude parts, a unit price list or discount rate valid throughout the year must be included.
What values should the maintenance report contain?
At a minimum it should include suction and discharge pressures, compressor and fan currents, indoor and outdoor air temperatures, water inlet and outlet temperatures (in water-based systems) and the alarm history. The values should be recorded per unit and in the same format at every visit.
How many hours should the response time be?
It varies with how critical the unit is. A few hours is generally considered reasonable for critical places such as a server room, hospital or production area, and the next business day for office and residential use; the time must be written in the contract in hours.
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