AquaTherm 24HBQB not blowing hot air issue

[Newbie757]

Hi all,

My condo have AquaTherm heating system and a Rinnai tankless water heater that runs together. The heating have been working fine all winter up until a couple days ago after I turned my main water valve off to change out some hardware in my shower. I bled the pipes after I turned the water off and after the water was turned back on. Rinnai water heater works just fine however my AquaTherm is no longer blowing hot air when heat is turned on.

I went to the attic to see if the unit is running, it is, I can hear it’s taking water and I also try turning the AC on which it works.

Does anyone know how to fix this issue or know what might have happened?? Perhaps something tripped and stopped the unit from taking hot water to blow hot air? Please help.

 

[Fitter30]

Either the pump isn't running or the coil in air handler is air bound. Look at page 7 for air removal.

https://firstco.com/wp-content/uploads/2021/08/IAM1010.pdf

 

[Sponsor]

 

[Newbie757]

Either the pump isn't running or the coil in air handler is air bound. Look at page 7 for air removal.

https://firstco.com/wp-content/uploads/2021/08/IAM1010.pdf

Thank you, I have a Rinnai tankless water heater and wondering if the steps are still the same. There are plenty of valves since the lay out of the unit is different, I am going to provide pictures once I returned home. I have turned the Air Handler off since 2-3 days ago and only turned on during troubleshooting so i hope that didn't ruin the pump or anything else.

 

[GrumpyPlumber]

Feel both feed and return side of the hydronic water lines at the unit, if one side is cold then Fitter30 got it, you're probably air bound though it's possible the pump is the problem, the coincidence is too strong, you may need to flush the return side down at the tankless and push out the air.

 

[Newbie757]

Feel both feed and return side of the hydronic water lines at the unit, if one side is cold then Fitter30 got it, you're probably air bound though it's possible the pump is the problem, the coincidence is too strong, you may need to flush the return side down at the tankless and push out the air.

I will give the flush a try once I am home. I will also post pictures of the tankless water heater and AquaTherm heater configuration for other instructions as well. I am a new condo owner and don't want to damage anything because of my inexperience but is willing to try to figure it out! thank you!