Help! Weird smell in house

homeowner17

I just moved into a house and find theres a weird perfumey/detergent-like smell when the radiant floor heating kicks on. It’s run by Navien ncb-190/080h combo-boiler. The house was a reno (completed in 2023), and they did a brand new subfloor and laid pine engineered hardwood floors and ceramic tile. I notice it the strongest in the mud room where the laundry is and there’s tile in that room. Anyone ever experience a weird perfume smell when running the radiant heating system? The temp in the photo says 137F but when I checked earlier it said 152F.

PC7060

I suspect someone spilled Tide or another liquid detergent on the floor and the heat is activating the scent. Check under the washer machine and dryer.

homeowner17

That was my thought at first too. But they haven’t lived in the house since June. Do you think it’s possible that the smell would still be that strong and potent? It’s a built-in staked washer dryer so it would be difficult trying to get it out. It’s so strong that even my coat hung up in the closet smells like that smell when I’m outside. My hair smells like it as well. It’s not just the room that smells, it clings to my clothing and hair.

mattmia2

Make sure the washer isn't leaking too. If it is soaked in to the floor it could hang around for years. Is there a mixing valve for the floors? 130 is way too hot for radiant.

homeowner17

I pulled out the washer and dryer and there were no leaks. I cleaned the floor just in case. The smell is still in the house when the heat kicks on. Where would I check to see if there’s a mixing valve? The boiler says 165 F when the heat kicks on. Zone 1 furthest to the right is the in-floor heating. @mattmia2

mattmia2

there is a thermostatic mixing valve right here:

Jamie Hall

A good chunk of the problem is that that water is much too hot for a radiant floor. Even if it isn't some strange spill problem, that is hot enough so that the tile adhesive and engineered flooring will be outgassing and will for years if you leave it at that temperature. The supply to the floor should never get over 110 F.

homeowner17

I took the temperature of the piping that runs to the flooring system and it was 155 F at the areas I circled in yellow (upstream of the mixing valve). But then I took the temperature of the tile floor and it was only 105F and the hardwood was 100F. @Jamie Hall

Jamie Hall

Yeah, the floor will be cooler. It radiates into the space, right? But that doesn't mean that the adhesive and flooring is cooler in contact with the hot pipe.

homeowner17

thanks @Jamie Hall how would I adjust the mixing valve to lower the temperature on zone 1? I think the water heater has to stay high around 160 F for the second floor radiators that are on zone 2.

Jamie Hall

I'm not at all convinced that that mixing valve is installed properly — the ones I've seen have the hot coming in one side, the cold (in this case the return) coming in the other, and the output from the centre pipe…

But… the black cap on the valve should turn to set the output temperature.

Kaos

Also a modcon running at 160F means you get no condensation, runnig the same efficiency as a standard boiler.

Most likely either outdoor reset is not installed or the curve is not set properly.

By running the system that hot during the shoulder season you are wasting around 10% fuel. I would figure out what the issue and adjust. A well set up reset curve should mean your zones are running most of the time.

This might also help with your too hot floor heat as it looks like that is a fixed adjustable bypass (not thermostatic). By dropping the temperature for the rads, it means that it will also drop the water temperature for the floor heat.

mattmia2

even without odr, if the only dh loads are radiant you can change it to fire at the temp for the floor.

the mixing valve could be frozen.

homeowner17

@Jamie Hall I should have someone out to look at it. Because even the return pipe is quite hot, too hot to touch and hold when the system is on. So the mixer if it actually works and was installed properly, likely wouldn’t cool the water down that much. I added of close up photo.

@Kaos yes the tankless water boiler I noticed will be sitting at around 110 F when the radiant floor isn’t on, then it’ll kick on and jump up to 165F. It’s does this constantly throughout the day and night.

Kaos

So that is not a thermostatic bypass. Looks like it is set to zero bypass so that is why you are having issues.

Simple think you can do is crank the floor heat and go to your boiler. Adjust the bypass until the water above it is feels like a nice hot bath. You want that water around 110F to 120F.

Eventually figure out why you don't have proper outdoor reset control. Getting this working properly is worth it for the fuel savings.