A thermostat RFQ should make it possible to select the right controller before price becomes the main conversation.
This guide is for HVAC buyers, distributors, importers, contractors, system integrators, OEM product managers and procurement teams requesting quotations for room thermostats and HVAC controls. It focuses on the information that materially affects product selection, quotation accuracy and project risk.
A useful thermostat RFQ should describe the HVAC application first, then the electrical and control requirements. For fan coil projects, that means pipe arrangement, fan type, valve signal and required inputs. For underfloor heating, it means water or electric heating, load or actuator details, sensors and zoning. For boilers, it means the heat-source control interface and thermostat power arrangement.
Communication, mounting, appearance, language, quantity, certification, packaging and OEM requirements come after the control fundamentals. A short RFQ with the right technical information is usually more useful than a long specification copied from a previous project.
Suppliers receive enquiries like this every day: 'Please send your best price for WiFi thermostat, 500 pcs.' It gives a quantity and a feature, but it does not tell anyone what the thermostat is expected to control.
A WiFi fan coil thermostat, a WiFi electric-floor-heating thermostat and a WiFi boiler thermostat may look similar from the front and be completely different products internally.
If the supplier responds only with a price list, the buyer still has to work out whether the quoted model fits the application. If the supplier guesses, both sides may spend the next several emails correcting the original assumption.
The RFQ does not need to be long. It needs to remove the important unknowns.
The first line of a good RFQ can be very simple.
For example: 'Room thermostat for 2-pipe fan coil units in a hotel renovation,' or 'Thermostat for 230V thermal actuators in an 8-zone water UFH system,' or 'Battery-powered room thermostat for On/Off boiler control in existing apartments.'
That one sentence immediately narrows the product family and gives the supplier context for the questions that follow.
Application is more useful than starting with a model number copied from another brand. Equivalent-looking products do not always use the same outputs, wiring or control logic.
Fan coil thermostat enquiries should normally identify the pipe arrangement, fan, valve and supply/control requirements before optional connectivity is discussed.
RFQ Item | Typical Information | Why It Changes Selection |
Pipe system | 2-pipe or 4-pipe | Determines heating/cooling output logic. |
Fan | AC 3-speed or EC 0-10V | Requires different fan-control outputs. |
Valve | On/Off or 0-10V; voltage where relevant | Determines actuator/valve interface. |
Additional control | Room card, window input, external sensor, dry contact, etc. | May require extra physical I/O. |
If the project has mixed FCUs, say so. A hotel or office renovation can contain different fan-coil generations across floors. That information may lead to a configurable platform rather than several unrelated thermostat models.
EC fan is useful information, but the RFQ should ideally state the required control signal. Many room-control applications use 0-10V speed control, but the equipment documentation should be checked.
Likewise, 'modulating valve' is not enough if the supplier needs to know whether the required interface is 0-10V, three-point/floating or another signal.
The thermostat should be selected against the equipment interface, not against a broad equipment label.
The word 'floor heating' can hide two very different electrical jobs.
In water underfloor heating, the thermostat typically controls a thermal actuator directly or through a wiring center. The RFQ should state actuator voltage, normally closed or normally open where relevant, zone quantity and whether boiler/pump demand is coordinated through a wiring center.
In electric floor heating, the thermostat may switch the heating load directly. The buyer should provide supply voltage, expected load/current and floor-sensor requirements.
A thermostat faceplate can be shared across product versions while the relay rating and internal circuit are different. This is exactly the kind of difference an RFQ should make explicit.
Boiler enquiries often become confusing when the requirement is written only as '2-wire' or 'dry contact.'
A dry contact describes how the thermostat can switch the boiler circuit. It does not by itself explain how the thermostat is powered. The room unit may be battery powered, mains powered or part of an RF thermostat-and-receiver arrangement.
For retrofit projects, state what wiring is available at the existing thermostat position and whether new wiring is acceptable. If possible, include the boiler make/model or the relevant control-terminal information.
That prevents a modern mains-powered wall thermostat being quoted for a location that has no suitable power supply.
Most room thermostats use an internal air-temperature sensor, but some applications need more.
Electric floor heating may require an external floor sensor. A fan coil project may need a remote room sensor because the thermostat location is unsuitable for representative temperature measurement. Other applications may use an external sensor for a specific control or monitoring purpose.
If an external sensor is required, include sensor type/specification where known, cable length requirements and what the sensor is expected to do.
Do not assume that an 'external sensor input' on two products performs the same function.
Writing 'WiFi + Modbus required' tells the supplier which interfaces are wanted, but not why.
For WiFi or Zigbee, explain whether the objective is end-user app control, multi-room management or integration into a particular smart-home ecosystem. For Modbus, say whether the project needs BMS monitoring only or supervisory read/write control.
If specific Modbus points are important, request the register map before approval. If the BMS must write setpoint, mode or fan command, that should be checked before the product is ordered.
Connectivity is easier to evaluate when the supplier understands the control architecture behind it.
A thermostat that is electrically correct may still be awkward to install.
State whether the project requires flush/in-wall mounting or surface mounting, and identify the wall-box format if it is fixed by the project. For retrofit work, photos or dimensions of the existing installation can be more useful than a general statement such as 'European standard box.'
Also state any maximum front dimensions or depth constraints that matter to the design.
Installation details are inexpensive to resolve during RFQ stage and expensive to discover after the product arrives.
Include the available supply at the thermostat location: for example 230V AC, another specified supply, battery operation or no permanent power.
This is especially important in renovation projects. Existing wall wiring may have been designed only to switch a boiler circuit and may not provide neutral or permanent power for a connected thermostat.
For fan coil controls, confirm the controller supply and the voltage expected at fan and valve outputs. For heating controls, distinguish the thermostat's own power from the load it switches.
A wiring diagram attached to the RFQ often answers these questions faster than several paragraphs.
A request for 1,000 thermostats is useful commercially, but procurement should also explain whether those 1,000 units are one configuration.
A project might require 700 white WiFi units, 200 black Modbus units and 100 special room-card versions. Another buyer may expect one hardware platform with configuration differences. Those are very different quotation and production questions.
Break the quantity down by application, communication, color and electrical configuration where those differences are already known.
For an early-stage project where the final mix is not known, say that clearly. The supplier can then quote the likely base configurations and identify which choices affect price.
If the buyer wants samples, explain what the sample is intended to prove.
A visual sample checks appearance. An engineering sample may need to be wired to an FCU, boiler, actuator or BMS. A pilot batch may be used to verify installation across several room types before a full project order.
For technical samples, request the manual, wiring diagram and communication documentation at the same time. A thermostat sitting on a desk cannot prove much about integration.
Where the final project is large, approving one representative configuration before mass production can prevent expensive corrections later.
For brands and importers, customization can include logo, packaging, user-interface language, model label, manual, app presentation, firmware behavior or hardware changes.
Put these into categories. A private logo and carton are very different from changing output logic or developing a new PCB.
The RFQ should identify what is required for launch and what can be considered later. This helps the supplier distinguish normal product configuration from engineering work and gives the buyer a more realistic view of tooling, testing, MOQ and lead time.
A long wish list is not a better OEM specification if nobody has decided which items are commercially necessary.
Do not write only 'CE required' and assume the compliance discussion is complete.
Tell the supplier where the product will be sold and which product configuration is being evaluated. Connected products, radio versions and different electrical loads can involve different technical documentation and test considerations.
Ask for the relevant declarations, reports or supporting documentation needed by your company before approval. The exact requirement depends on the product and market, so it is better to align compliance documentation during supplier qualification than after packaging has been printed.
For a new thermostat supplier, a few documents can reveal a great deal about how easy the product will be to work with.
· Wiring diagram and terminal definition.
· Installation/user manual for the proposed model.
· Technical datasheet with electrical ratings and sensor information.
· Modbus register map where Modbus is required.
· Gateway or app architecture information where relevant.
· Available language and parameter list for project versions.
· Certification/compliance documents appropriate to the target market.
· Product dimensions and mounting information.
If the basic technical package is unclear, negotiating the final carton artwork or annual rebate is premature.
A good RFQ does not remove every question. It makes the remaining questions specific.
If a buyer says '3-speed FCU, 230V valve, Modbus,' the supplier may still need to confirm 2-pipe versus 4-pipe, heating/cooling changeover logic, room-card input or whether an external sensor is required.
That is normal. What should be avoided is silently choosing a configuration because it is the closest item in the catalogue.
For buyers, technical clarification is not a sign that the supplier is difficult to work with. The quality of the questions often tells you whether the supplier understands the application.
The following information is enough to make most first quotations substantially more useful:
· Application: FCU / water UFH / electric UFH / boiler / radiator / other.
· Project type: new build / retrofit; residential / hotel / office / other.
· Target market/country.
· Quantity and expected split by configuration.
· Thermostat power supply.
· Controlled equipment and required output signals.
· FCU: 2-pipe/4-pipe, AC/EC fan, fan signal, valve type/signal.
· Water UFH: actuator voltage/type, zone quantity, wiring center requirements.
· Electric UFH: supply voltage, heating load/current, floor sensor.
· Boiler: control interface, existing wall wiring, battery/mains/RF preference.
· Required sensors and inputs: external sensor, room card, window contact, etc.
· Communication: WiFi / Zigbee / Modbus / RF and what it is expected to do.
· Mounting: flush or surface; wall-box requirements.
· Display/interface: color, language and key UI requirements.
· OEM requirements: logo, packaging, firmware, app or hardware changes.
· Required technical/compliance documents.
· Sample or pilot requirement and what needs to be tested.
· Target timing for sample approval and project delivery.
Not every RFQ needs a formal technical specification. In many cases, three attachments are more useful than another page of text.
For an FCU project, attach the fan-coil wiring diagram or control schematic. For a boiler retrofit, attach the boiler model/terminal diagram and a photo of the existing thermostat wiring. For UFH, attach the manifold/wiring-center arrangement and actuator information.
For a BMS project, include the intended point list or control sequence if it already exists.
The supplier can then compare the proposed thermostat against the real system rather than against a description that may use different terminology.
A well-prepared RFQ does more than improve the quotation. It gives the buyer a chance to see how the supplier thinks.
Does the supplier notice that the EC fan signal has not been specified? Do they ask how the boiler thermostat is powered? Do they request the BMS point list? Do they distinguish electric UFH from water UFH before recommending a model?
A supplier that only returns a price may still be suitable for a straightforward commodity purchase. For controls that have to match real HVAC equipment, technical interpretation is part of the value.
The quotation process is therefore an early test of future project support.
Price comparison becomes meaningful only after the compared products are technically close enough.
One quotation may include WiFi, Modbus, external sensing and a configurable valve output while another covers only the basic control function. The cheaper number is not necessarily a cheaper solution; it may simply be a different product.
A clear RFQ reduces this ambiguity. Suppliers quote against the same application and the buyer can see where genuine feature, service and commercial differences remain.
That is the real purpose of a thermostat RFQ: not to make procurement paperwork longer, but to make the decision cleaner.
CosyClimate provides thermostat and HVAC control solutions for fan coil units, water and electric underfloor heating, boilers, radiator heating and related multi-zone applications. Product platforms can include WiFi, Zigbee, Modbus, RF, external sensing, room-card functions, AC/EC fan control and different valve or heating outputs depending on the application.
For a quotation, send us the HVAC application, wiring or equipment information, required control signals, communication, mounting, quantity and any OEM requirements. If some items are still undecided, we can help identify the technical questions that need to be confirmed before final model selection.
Contact CosyClimate to discuss your next HVAC control project.
Email：info@cosyclimate.com
Phone：+86 13520339098
Add：Tongzhou District, Beijing, 101199 China
