Proactive gas range replacement?

[Nathan McBride]

I had a repairman at one of my properties the other day to look at a gas wall heater. 

The heater is of 1940s vintage and a big time fire and CO hazard, so now I have some new heaters en route from Amazon to replace all of the outdated heaters on the property. 

While he was there, I had him look at the pilot light on an oven that was acting up. He recommended that I proactively replace the ranges that have continuously lit pilots, again because of the fire/CO risks. 

In this particular multi family property there are four of those ranges, so probably looking at around $2-2.5k all in for installing new ranges. 

My question is whether or not it is worth proactively replacing these ranges. I’m going to replace the one that’s acting up and one in an empty unit as an opportunity to upgrade to stainless, but the other two work fine, and the tenants recently renewed their leases. 

Does anyone else recommend replacing ranges proactively? I have CO/smoke detectors in the units.