What a combi boiler lead should cost

Why industry averages are the wrong starting point

Short answer: averages mix markets, seasons and sales teams that look nothing like yours.

You'll see "average cost per lead" figures in agency blogs and software reports. For a boiler installer they're close to useless, for three reasons:

• Markets differ enormously. A combi lead in a dense, competitive city costs something very different from a lead in a small prairie town.
• Lead definitions differ. Some reports count every phone tap. Others count only qualified enquiries. A "cheap" lead might be a wrong number.
• Your sales process matters more than the lead. Two installers buying the same leads can end up with completely different costs per install, because one answers every call and returns quotes the same day and the other doesn't.

The only benchmark that matters is your own margin and your own conversion rates.

Step 1: find your margin per installed job

Short answer: use gross margin, not revenue, and use a typical job, not your biggest one.

Gross margin here means the installed price minus equipment, materials, direct labour and subcontracted costs (venting, electrical, permits). Don't use revenue; a $9,000 job with $6,000 of costs leaves $3,000 to cover marketing, overheads and profit.

Pull the last 20 or so combi and boiler replacement jobs and find the median margin. If your work splits into clear types, calculate each separately:

These are examples only. Your own figures will differ.

Step 2: measure your conversion rates

Short answer: two rates matter: leads to booked estimates, and estimates to sold jobs.

1. Lead-to-estimate rate. Of the genuine enquiries you receive (not spam, not existing customers, not job seekers), how many book an in-home or virtual estimate? Example: 50%.
2. Estimate-to-sale rate (close rate). Of the estimates you run, how many become sold jobs? Example: 40%.

Multiply them: 50% × 40% = 20%. In this example, one in five genuine leads becomes an installed boiler.

If you don't track these yet, a simple shared spreadsheet is enough. Our lead tracking service sets this up, but you can start on your own today with three columns: lead source, estimate booked (yes/no), job sold (yes/no).

Step 3: decide what share of margin you'll spend

Short answer: pick a percentage of gross margin you're comfortable investing to win a job, and stick to it.

There's no correct answer, but many owners find a range they're comfortable with by asking: "If I paid this much to win the job and kept the rest, would I take that job again?" For this example, we'll use 20% of gross margin.

$3,000 × 20% = $600 maximum marketing cost per installed combi.

Step 4: work backwards to cost per lead

Short answer: multiply your allowed cost per install by your lead-to-install rate.

$600 × 20% = $120 maximum cost per genuine lead.

And for booked estimates: $600 × 40% close rate = $240 maximum cost per booked estimate.

Now you have three numbers to judge any campaign against:

If Google Ads is producing combi leads at $90 each and your rates hold, the channel is profitable and you could probably spend more. If leads cost $180, you either need better conversion, a higher margin or a cheaper channel.

Step 5: adjust for add-ons and lifetime value

Short answer: add the extra work and future work a typical combi customer brings.

The first job is rarely the only revenue. A combi customer may also buy:

• an annual maintenance plan
• radiator replacements or zoning upgrades
• a water treatment system or expansion tank replacement
• referrals to neighbours

If those add, say, $800 of gross margin over the first few years on average, your effective margin per customer becomes $3,800, and your ceiling per lead rises to $152 using the same rates. Be conservative here. Count only add-ons you actually sell regularly, and only margin, not revenue. If you want to build those repeat services into a system, our sister site Boiler.Management covers maintenance-plan marketing.

Common traps that distort the numbers

Short answer: counting the wrong leads, forgetting the management fee and ignoring timing.

• Counting every call as a lead. Strip out spam, existing customers, suppliers and job seekers before you divide.
• Leaving out the management fee. Your cost per install includes the agency or staff time, not just ad spend.
• Judging too early. Boiler sales cycles can run weeks or months. A lead from March might sign in May.
• Mixing repairs and replacements. Track no-heat repair calls separately.
• Letting rebates inflate the budget. Where a real rebate applies, like SaskEnergy's listed $800 for an eligible combi as of October 2026, it may lift your close rate. It doesn't add to your margin.
• Ignoring missed calls. A lead that rings out still cost you money. Fix answering before you buy more leads.

A complete worked example

Short answer: put it all together and the decision becomes obvious.

An illustrative installer spends $2,500 on combi ads plus $2,998 on a monthly plan in a given month: $5,498 total.

• Genuine leads: 40
• Booked estimates: 20 (50%)
• Installs: 8 (40% close)
• Cost per lead: $137
• Cost per estimate: $275
• Cost per install: $687

Against a $600 ceiling, that's slightly over. The fix might be better landing pages to lift the lead-to-estimate rate, faster quotes to lift the close rate, or tighter targeting to cut wasted clicks. With a $3,800 effective margin including add-ons, the ceiling rises to $760 and the month is profitable.

Your checklist

Short answer: five numbers to know before you spend another dollar.

1. Median gross margin per installed combi or boiler
2. Lead-to-estimate rate over the last three months
3. Close rate on estimates
4. The share of margin you're willing to spend to win a job
5. Your resulting ceilings: cost per lead, per estimate and per install

When you have them, compare every channel against them every month. The pricing page shows what our plans cost, so you can plug them into this method before talking to us. If you'd like help setting up the measurement, see combi lead generation or get in touch through the contact page.