Two written quotes for the same softener can differ by a wide margin and still describe different jobs. One may include removing the old unit, a bypass valve, and the first fill of salt. The other may leave those out and add them later as separate charges. Before you choose the cheaper number, put the quotes side by side and make sure they cover the same work.
Put every quote in the same columns
Ask each company to write its quote in the same format, or make your own table with one row for each item below. Mark each quote as included, not included, or unclear. A blank cell is not a yes. Most of the difference between two quotes will show up in the rows that someone left blank.
Also write down the unit model, the control valve type, the tank size, and the stated hardness and daily water use that the sizing is based on. If two quotes use different assumptions, the totals are not comparable even when the equipment looks similar on paper.
The line items that decide the total
Check these items in each quote:
The unit itself, including whether it is new or refurbished, and the warranty length and what it covers, such as parts only or parts and labor.
Removal and disposal of any existing softener, and whether the old unit has to be hauled away by you.
A bypass valve, the connections to your plumbing, and any fittings or adapters needed for your pipe material.
The drain connection, including whether a new drain line, a drain saddle, or an air gap is part of the price, and how far the discharge point is from the valve.
Electrical work, such as whether a new outlet is needed near the unit or whether the company expects you to supply one.
Permit fees and who pulls the permit. Ask whether the permit is listed as a separate charge.
Delivery, setup, startup, and programming of the control head.
A first load of salt and the salt you will need after that, plus any pre-filter or other add-on equipment.
Before and after water tests, and whether the company will show you the readings.
What a low total often leaves out
A low total is sometimes a starting price with the most expensive parts of the job left off the page. Watch for phrases like 'plus materials,' 'site conditions may apply,' or 'to be determined after inspection.' These do not have to mean a company is dishonest, but they do mean the final bill is not yet known. Ask what would change the price and what the company would charge for each change.
Financing is another place where the total can move. If a quote is paid over time, ask for the cash price and the full cost with financing, then compare both figures against the other quotes. Also ask whether a deposit is refundable and when it is due, since those terms affect how much money is committed before the work is finished.
Questions to send back before you sign
Send each company the same short list of questions and compare the answers in writing:
Is this price fixed for the work described, or is it an estimate?
Which items are included, and which would be billed separately?
What hardness and water use did you assume when sizing the unit?
Who pulls the permit, and what does the permit cost?
What exactly does the warranty cover, and who handles a claim?
If something unexpected is found during installation, how will you contact me, and do I have to approve the extra charge before the work is done?
When you have answers from each company, pick the quote that gives you the most complete job for the price, not the one with the smallest first number. For a view of how the site scores companies, see the rating methodology.