I need a new running watch with heart rate zone alarms, interval timers and GPS. Don’t really need any other bells and whistles at this point. Don’t mind considering older models, would something like a Forerunner 235 cover this?

Pretty much any Forerunner will cover that.
The 235 is an older model, replaced by the 245, but the cheaper 45 will do all you need as well. I think if you can find a 35 that’ll work as well, again, it’s an older model.

The wife has just bought a forerunner 45s. Pretty sure it does all that. £60 from eBay. Has a small scratch but works fine.

I’ve been using the 245 for a couple of years now mainly for integration with Connect/Edge 1030. I had the Polar M400 before which was also very good but not Connectable (see what I did there…?) which was the only reason for swapping as I think the Polar Web app is better than Connect.

It’s been ace. Music version available if you must have choonz.

I’ve got a 235. Not sure how you’d do an interval timer apart from loading a specific workout on it (which you can easily create) – it’s not like the old Timex Ironman watch I had where you could set interval timers on the watch itself very quickly.

Great watch though with good battery life & plenty more features than I need.
I seem to remember there being a subtle difference between the cheapest Garmins and the next tier up – something like you couldn’t create custom workouts, or something like that. It put me off, but the reality is I’ve not used that feature a great deal.
Found it – you can create a simple interval session, but not something more complex like you can with the higher end Garmins. On my 235 you can create a custom workout on Garmin Connect & then sync it to the phone.
Explained better here:

Can’t create custom intervals on the Forerunner 35 from running

I suppose what you intend to use it for will determine whether this is an issue or not?

I’ve just got a forerunner 55 to replace my polar m200. It’s got a little bit of a smaller face but shows more information! Gps accuracy seems very good and battery life also seems excellent. Would recommend it.

I recently bought a Forerunner 45s. Works brilliantly.