Does radiant heat take the warm water from the hot water tank?

Question

My hot water tank seems to be getting cold fast and I have radiant heat at the house. The tank is about 10 years old.

Answer 1

Depends...
If you have a boiler that looks like this
http://www.weil-mclain.com/netdocs/cgiframes.htm
then the boiler is firing the water and not stealing water from your hot water tank.. look for another big device in the basement that may look similar to this.

If you dont see anything that looks remotly like that and you have lots of vavles coming off your water heater, something like this
http://www.radiantcompany.com/system/open.shtml
then your water heater is providing power for both. The key is the valves(red boxes in picture). Also the brand of water heater polaris(same one at website) is a very popular water heater that is good for both radaint heat and domestic how water(sink shower water). In most cases you need a special water heater to do both tasks.

If your water heater is providing both there is a way to zone it so that it gives priority to the domestic hot water. If 10 years old and you only have a water heater it might be time to bring someone in to see if they can replace the heater(if needed) and can set it up right to give priority to the domestic hot water

Answer 2

The two unit idea is the better of the two scenarios which you put forth. The water in an instant heater system is not heated until there's flow through the system, so there will need to be a pump connected to provide the pressure necessary to circulate the liquid throughout the piping. You should also install the thermostat and relay system so that you're not just running hot water through the pipes when you don't need the heat. It must be nice to have an unlimited source of income, cause that's what it's going to cost you.

Answer 3

No, radiant heat has its own system of circulating hot water. You may need to turn the hot water setting higher.

Answer 4

if your talking about the large tank above the boiler, that's an air tank. no hot water is stored there. All your water is in the lines and the boiler itself.

Answer 5

It depends on how it was installed.
In floor heat should run off a boiler.