I recently purchased a house (3 stories, standalone, townhome-style) that has a ~10 year old hydronic radiant heat system, but the system seems a bit peculiar.
From the bit of research I've done, my understanding is that these systems usually need a separate boiler to heat the water in a closed system, but mine uses the same tankless hot water heater that is used for the rest of the home's hot water. As far as I can tell, this has resulted in an overly-complex piping and valve system to ensure that the radiant heat water doesn't flow back into the normal tap. The radiant water is piped to wall-mounted radiators on each floor, except for the first floor, where it seems
to be piped through the floor? (Although there are cold patches, so I'm not even sure)
I've had a few problems with this system:
- Whenever the house has been heating, I've had a harder time getting hot water from faucets, etc, presumably because it's competing with the radiant heating
- There's a "bubbling" sound that comes from the wall-mounted radiators whenever the system is on, and it's been getting louder over the last few months (I started noticing it after we had a plumber come and do some work to try to fix the hot water tap problem)
I have a few questions:
- Could the "bubbling" be indicative of a leak? Should I try to get the original plumber to make sure they didn't cause it? Or how else should I address this? (Incidentally, the house also has a leaky roof and bad siding, but that's the exterior - the rest of its plumbing has been fine)
- In general, what are my options to improve the situation overall? Should I look into getting a boiler for the radiant heat system, to separate it from the water heater? Alternatively, the house doesn't have any kind of A/C, so it's likely that I'll soon purchase something like a few ductless mini-split systems, which can also do heating. Should I consider just getting rid of the hydronic system altogether after I get the mini-splits? If so, what would that involve?
Thank you in advance for any suggestions.
Here's a video of the bubbling sound:
And here are some images of the system: