The pipes to our kitchen sink froze a coupke of days ago. As in past winters, we put a small space heater under the sink to thaw them out. We did the same thing this time and it worked except that we're only getting cold water. When we turn it over to hot it's just trickling out. This has never happened before.We have turned the faucet to hot and all the way open, and checked our water meter and there's no activity, so we're thinking it's not a burst pipe. We figured if a pipe had burst, the needle on the meter would be spinning. No other faucets in the house are affected. Any ideas?