HVAC Help

[ltbaney1]

So I live in a condo, we have what I believe is called "hydronic heat" from my rough understanding and what i can see. hot water flows from the water heater up to a unit in the attic, with a radiator in it and fan blows accross the radiator forcing hot air through the ducts? I replaced my water heater on Christmas day, and now my heater just blows room temp air. i triple checked the valves i closed when i did the water heater and they are all they were before I replaced it. I pulled the side panel off the unit in the attic, and it looks pretty basic, one side for heat, one side for AC and a big fan in the middle. the only thing i can think of is that the stupid little circulator motor died in the unit. i checked and it had power but did not try to turn the heat on while i was up there. the pic on the left is the heat side and the right is the AC side. I believe. the cirulator motor in question is in the left with a black and white wire to it. with my contact tester, both wire are hot?

Appreciate any help or ideas.

 

[TrollerDave]

Did any water drain out? Maybe got air in there that needs to be bled out?

 

[NicPaus]

When you drained the water heater probably lost prime on the pump.

 

[monkeyswrench]

Sounds like the circ pump is either bad, or not getting a feed. That's the same type of setup we have here. (Being on propane, for water heater, we keep it as backup.)

 

[lbhsbz]

I would start with identifying both the supply line to the attic unit and the return line, then cracking the return line to bleed it (normal water pressure should make this work)....and see what happens. A pump in the attic will not self bleed/prime.

 

[ltbaney1]

Did any water drain out? Maybe got air in there that needs to be bled out?

yes, i got wet changing the water heater. I did not even think of it being looped system and the possibility of needing to be bled. thank you

 

[ltbaney1]

sounds like im going to try to bleed the system tonight. am i overthinking it by thinking i should remove the cap with the red dot, open the valve circled in green and turn the unit on via thermostat and wait to get bubbles / water?

 

[dezertrider]

As long as you left the piping the same at the water heater you probably lost prime on the pump. Some times plumbers cut off the hot water return back tot he water heater.

 

[ltbaney1]

As long as you left the piping the same at the water heater you probably lost prime on the pump. Some times plumbers cut off the hot water return back tot he water heater.

piping at the water is exatly the same with the exception of the flex lines. there is a T on the cold and hot side going up the attic each with a valve. i did not touch those valves, just the valves to the heater. but never considered that those lines would need to be bled. which thinking about it makes total sense and will be attempted tonight.

 

[fishing fool]

If the valves were blocked in at the water heater going to the pump, the system was blocked in and nothing was lost. Check the pump to make sure it is running. If running feel the lines, one should be hot (supply) and the other colder (return). If pump is on and no change in temp the pump is not pumping. Now whay is it not pumping? loss of prime or bad impeller.

 

[Mandelon]

I doubt this applies to your situation, but often replacing a water heater dumps some sediment into the lines, and the installers don't always bleed off some water before filling and connecting the new one. Then you have to clean all the aerator screens in the faucets because the end up with no flow.

 

[Riverbound]

sounds like im going to try to bleed the system tonight. am i overthinking it by thinking i should remove the cap with the red dot, open the valve circled in green and turn the unit on via thermostat and wait to get bubbles / water?

View attachment 1474246

Hook up a hose to this valve and run it to either the tub or outside open the valve purge the system. Once it’s a steady stream for a good minute or so close valve and it will work.

Very common problem for where you live.

 

[ltbaney1]

Hook up a hose to this valve and run it to either the tub or outside open the valve purge the system. Once it’s a steady stream for a good minute or so close valve and it will work.

Very common problem for where you live.

thank you, will do that tonight.

 

[boatpi]

Experts, I have this same system in part of the house that I am about to move into. Not too keen on it. Your thoughts, and I am in Vegas.

 

[ltbaney1]

Experts, I have this same system in part of the house that I am about to move into. Not too keen on it. Your thoughts, and I am in Vegas.

im by no means an expert, as this thread will tell you. but i can tell you, in general its ok. our system is OLD, the condesor unit outside is from 94-95 if memory serves. and im pretty sure the attic unit is original from 90-91. my biggest gripe, and i dont think it has to do with this style of HVAC but rather my duct sizing and layout is uneven temps. I have a 2 story 1300 sqft condo, and from up stairs to down stairs can be pretty far off. id love to bring someone like @Riverbound in and have it all done so it works how i want, i just dont have the coin so i will keep patching it up as long as it keeps working.

 

[monkeyswrench]

@boatpi , I don't know about efficiency. My system runs a 150g water heater, so hot, long showers are fine. I can tell you, that when the "heater" kicks on, the shower temp drops. That part sucks. We hardly use ours though, a couple times a year maybe. If we get home late it brings up the Temps in our 2000sqft home quickly, so we'll turn it on instead of the stove.

 

[Riverbound]

thank you, will do that tonight.

Text me if you have an issue and I can walk you through it.

 

[Riverbound]

Experts, I have this same system in part of the house that I am about to move into. Not too keen on it. Your thoughts, and I am in Vegas.

They are pretty common and work well depending on how your hot water system is set up. You will need a larger than normal hot water system.

Hydronic heat is nothing new and is a very common way to heat. They are very simple and failure proof.

 

[Riverbound]

im by no means an expert, as this thread will tell you. but i can tell you, in general its ok. our system is OLD, the condesor unit outside is from 94-95 if memory serves. and im pretty sure the attic unit is original from 90-91. my biggest gripe, and i dont think it has to do with this style of HVAC but rather my duct sizing and layout is uneven temps. I have a 2 story 1300 sqft condo, and from up stairs to down stairs can be pretty far off. id love to bring someone like @Riverbound in and have it all done so it works how i want, i just dont have the coin so i will keep patching it up as long as it keeps working.

I got you when you’re ready we have some cool stuff to retrofit these types of systems.

 

[TrollerDave]

Experts, I have this same system in part of the house that I am about to move into. Not too keen on it. Your thoughts, and I am in Vegas.

I lived in an apartment for a year with this type of system. It worked well and kept the place warm. The one thing we had an issue with is condensation and mold build up on the inside of the windows. It didn’t seem to dehumidify like a gas furnace. I’m not sure if it is a common thing with these type of units or just to the apartments where I lived. Maybe being in the dry climate of Vegas, it might not be an issue.

 

[boatpi]

Thanks everyone.

Our new to us house in Las Vegas when I move in and probably another month and a half has this system in one section of it. There is three separate HVAC systems all heat pumps except for this one.


I just spent a considerable amount of money bringing in natural gas in the street. I have to change out one of the units to a 5 ton heat pump but as the experts know when it gets to 30° in the desert, you don’t get much heat out of a heat pump and that’s probably why they did this. It’s in the master bedroom And hallway area.

Is it the same property? The property is built in 1995 so we’re just updating a lot of systems and spending insane money getting the place ready to move in for my final resting spot.

 

[ltbaney1]

Just wanted to jump back on here and say thank you to everyone that suggested "bleeding the system". I finally had a chance to get back up in the attic last night, and bleeding it took care of the issue. what i wound up doing was making a foot long clear hose with hose repair ends and then hooking my garden hose to that and running it to the tub. I wanted a clear section because i was doing it solo and wanted to see when i got clear water no bubbles. it took about 1 minute to get clear water with no bubbles.