Is my wet radiator in short supply? It doesn't heat water as brisk as it used to. When I...

It doesn't heat water as brisk as it used to. When I turn the sink or shower on for hot water, I wait in the order of 2-3 minutes. Anything I can do about it without foremost costs?
Which compressor combo should I save?
Answers:    You did not say whether the heater be gas or electric. If it is an electric water heater probably one of the elements is any burned out or has too much of a calcium buildup on the element to properly boil the water. Replacement of the heating elements is duly easy and not too expensive. Elements cost between $10 and $25. Most water heaters own two and upper one and a lower one. It is usually the lower one that burns out.
How to say constant dampen pressure within home?
You left out part of the ask, but I am guessing you have an electric water space heater and the bottom element is out. Cost to replace will be less than $50.00 I am estimating.