So you are saying that your current primary residence will be converted to a income ( rental property) while you move to new property and use that( new one ) as your main residence.
There are no tax penalties as such but the net income from rental is taxable income. However, depending your longer term plans / aims you need to be aware of :
1.If you have owned the current property for at least two years and have used it as your main residence ( by both you and your spouse ) and you sell the property at a gain, up to $500,000 ( $250,000 for single filer) can be excluded from taxes.
2. When you convert a primary residence to a rental property, the basis of the property is generally your acquisition cost plus cost of improvements. During the rental period you have to recognize depreciation ( based on the value of the improvements i.e. total less value of land at time of purchase) based on 27.5 years life. This depreciation reduces your taxable earnings from the rental income but also reduces your basis. So when you sell the property, your gain in the property is increased by this depreciation. But it also has a secondary effect --- when the property is sold at a gain, all the gain up to the accumulated depreciation amount is treated as ordinary gain and taxed at your marginal rate while any leftover gain thereafter is treated as capital gain ( reduced tax rate ).
3. However, if you do choose to rent out and the market is good in the area, it is a good source of income --- i personally have had anywhere between 3 and five houses in mutliple states as rental properties and these have worked for me .