BCRider

It's likely that the wheel isn't correctly tensioned up then. So what is happening is that the spokes are becoming loose and "working" until they snap.

Optimally you would either tension and re-true the whole wheel yourself or have the shop do it. Some additional spokes will still snap over the next while since they were cyclicly fatigued by the poor tensioning but after the next few go and are replaced I would hope that it would be the end of it.

THe other option is to have the wheels re-laced with new spokes and correctly tensioned by the shop or yourself.

You can test your wheel right now to see how it is. Lightly tap all the spokes from the drive and non drive side with a screwdriver handle like you're playing a dulcimer or xylophone and listen to the tone. The drive side and non drive side spokes should all have about the same tone with the drive side spokes being noticably higher on average. If any of them sound low and dull then those are the next in line to break. If you tighten them up to where they are in close harmony with the rest you will likely save a busted spoke in the near future unless too much damage was done already.

The tone from them should be quite musical. It's hard to pass on such things over the web but if you know music you should hear tones from the spokes that are up around a middle C. Drive side being a little higher and non drive a little lower. Front wheels shoudl be matched side to side and all around at around a middle C or A below middle C. If they any are at or below the C below middle C then you should tighten those to bring them in line with the others and re-true as required.

This may not be perfect. But in the absence of a spoke tension guage it'll get you into the ballpark and give you a tool you can use to at least diagnose anything really off and serious.