Yes, we have done it for many years and continue to do it.
That is a technical question, we may have to ask more questions before we can answer that. In general unless there is a leak or you have a system that has been running for a while, you do not need to change or top up. However, we are glad to help figure out what is needed and get it fixed.
New people often move into old houses and find that they require more robust systems or the maintenance of the old systems is expensive. Sure we can help replace the old systems with the latest ones offering you more choices from the perspective of the number of products, affordability, and performance.
It really depends on when you started noticing the water marks on the ceilings. If it happened just after a winter freeze, it could be water pipes or anything else. But quite often if it seems like there is no reason, it could be that the "catch tray" of our airconditioning system has overflowed for a while and as such has rusted and now the water is seeping through the rust and falling onto the ceiling. It is best you get a home inspector as soon as possible to assess the damage and help you with information that could prevent further damage.
If there's a water pipe on the left side, right side or back of the house coming from just under the eves of the house, the pipe lets out water that has overflowed from the AC catch tray. Usually, the extra-condensed water from the AC unit runs to one of the bathrooms (sinks). But often it catches dust and eventually, it is stopped and plugged up. The water backs up and gets caught in a catch tray, letting the water flow through the pipe you see outside. When you see this, you need to go to the bathroom in which the flow sink is located and clear the clog. If the water that is dripping from the pipe is brown, it means the catch tray is rusting or has rusted, you need to get it replaced ASAP.
Typically just before the summer, you need to get your AC units examined and serviced (once a year), however, if your ACs run over time, you may have to get them serviced more than once a year. Our qualified specialist should be able to tell by looking at your AC and the area it has to cool and how long it is run.