When choosing a RO water purifier retailer in Coimbatore, certain things must be remembered in order to obtain original products, quality service, and proper after-sales service.

1. Authorized Dealer or Service Center
Brand Authorization: Make sure that the dealer is a company authorized representative for which you are intending to buy a product. They will be able to give you original products, and you will be able to receive official warranties and services.
Certifications: Make sure that the dealer is company certified to install, repair, and maintain.

2. Variety of Products and Brands
Variety of Options: Opt for a dealer that stocks an excessive variety of RO purifiers of an excessive number of brands (Kent, Aquaguard, Pureit, etc.). In this way, you can choose the best based on your requirement and price.
Product Knowledge: The dealer must be sufficiently knowledgeable about various models and specifications, so they can give you the right purifier based on your water quality and usage requirements.

3. Customer Reviews and Reputation
Online Reviews: Check online reviews or feedback on pages like Google, Justdial, or local review pages to know about the reputation of the dealer.
Word-of-Mouth: Get referrals from friends, relatives, or acquaintances living in Coimbatore. Word of mouth among the locals can prove to be a reliable source of dealers.

4. Warranty and After-Sales Support
Warranty Coverage: Ensure that the dealer has a well-established warranty policy. The standard warranty for most RO purifiers is equipment for 1-2 years and filters and membranes for 6 months.
Service Availability: Asking whether the after-sales services such as installation, repair, and maintenance are available with the dealer or not. The dealer should have a service center or technicians in case your purifier is faulty and they can repair it easily.
Annual Maintenance Contracts (AMC): A few dealers of a few products provide AMCs for maintenance. Check if the dealer provides this facility because it proves to be beneficial in the long term.

5. Installation and Maintenance Services
Professional Installation: Professional installation centers should be made available by the dealer. Check if the installation would be done free of cost or at a cost.
Timely Service: Ask them when they can install it and how long the average maintenance is. A good and timely dealer can turn into a great helper in case you have any problem with your purifier.
Local Service Reach: It is essential that the dealer has timely ability to reach you so that they can send the technicians in case you have a problem with the purifier. Select a dealer with good local reach in Coimbatore.

6. Post-Sale Support and Responsiveness
Customer Support: Select a dealer with good customer support. Make sure that they are easily available for any service-related complaints.
Repair and Spare Parts: Enquire if they provide access to spare parts and replacement filters and when they will send them. You do not have time to wait when a filter or part needs to be replaced.

7. Transparent Pricing
Transparent Pricing: Enquire if they give transparent pricing without any hidden costs. The price of the purifier, installation, and any other fees (filters, maintenance) must be clearly outlined.
Discounts or Deals: Verify whether the dealer provides any deals, discounts, or packages for RO purifiers and if replacement filters are available at discounted prices.

8. Return Policy or Trial Period
Trial Period: Some dealers might have a trial period or money-back guarantee for some time, in case the purifier does not meet your expectations. Verify if they have that facility.
Return or Exchange Policy: Ensure to look for the return or exchange policy if the purifier does not function soon after purchasing or does not fit your needs.

9. Post-Sales Training or Instructions
User Training: The proper dealer should provide adequate training regarding operation of the purifier, replacing filters, and maintenance check-up.
Troubleshooting Support: Ask if the dealer provides troubleshooting support or a repair manual for fixing common errors in the purifier.

10. Business Years and Experience
Experience: The dealers who have been in service for so many years would gain experience of managing various water conditions and various models of purifiers. They would suggest the proper solution depending upon the local water condition.
Settled Presence: A settled Coimbatore dealer will definitely give good service and support in the long term.

11. Service Area
Local Reach: Ensure the dealer is at your reach and services all areas of Coimbatore. A local wide-area dealer will have more accessible technicians and quicker service.

12. Compliance with Local Standards
Water Safety Standards: Make sure the dealer is aware of local water quality standards and can recommend a water purifier that complies with local regulations (e.g., product ISI certification).

13. Demo and Consultation
Free Demo: Some retailers provide free in-home demonstration so that you know how the functions and features of the purifier work. This is particularly useful if you are not sure which model would be best for you.
Expert Consultation: Select the retailer that provides expert consultation, making you aware of the advantages of various types of purifiers based on your water quality.

Summary Checklist:
Authorized dealer or service center
Most extensive array of products and brands
Best customer reviews and reputation
Clear warranty and after-sales service transparency
Professional service and installation centers
Transparency in prices without additional charges
Ease in availability of spare parts and filters
Having a reputed and experienced local dealer
Good customer service and after-sale support
Keeping the above points in mind, you will be able to find a good RO water purifier dealer in Coimbatore who provides the correct product and good service to your requirements.