Help needed: Hydronic heater problem and all local techs booked

yish

Thanks! Great idea!

Here you go. Let me know if you need any more details on any of the pictures or need me to take some more for some additional clarity.

http://flickr.com/photos/19634718@N00/sets/72157594443434340/

yish

Hydronic heating problems

I have (from what I have been able to ascertain) a hot water fan-coil central air heating system that I am having problems with. When I turn the thermostat on, the blower operates but I don't get any hot air from the vent's throughout the house. I went into the ceiling unit where the blower sits and found two pipes, one (inbound?) leading to first a recirculating pump and then onwards to a coil/radiator system. from their the pipe exits the unit parralel to the inbound pipe. Neither pipe ever got warm even though I ran the unit on for 30 minutes. I couldn't tell for sure if the recirculating pump was actually working since their was too much noise/vibration from the blower but I think it was. Any ideas on how to check? Any other ideas on what may be wrong? I believe the pipes are hooked up to my hot water heater in the garage since I don't see any other boiler/heating units. Any feedback would be much appreciated.

Brad White_164

Hydronic Problem

most likely. Possibly air-bound or insufficient fill pressure to get the water to circulate.

If there is a vent at the high fan coil unit coil, open it (key or coin vent perhaps). If air comes out but after a minute or so no water, you should check your system fill pressure. If a 2-story house, 12 PSI is about right as a minimum. If a 3-story house, use 18 PSI.

If you get water out of the vent, check the circulator, if it is running. Check power (disconnect switch? Should it be so simple.)

Is the boiler firing? You may have circulation, plenty of pressure but not fire in the boiler. (Water heater???) Jeeesh. Hope that does not take care of your shower needs, but that is another thread.

That the fan runs is a little odd but not uncommon. Often an aquastat is used to keep cold air from blowing. The aquastat holds off fan operation until the return pipe is warm.

How old is the system and has it worked in the past?

yish

Hydronic problem

Right before the circulating pump, the pipe leading up to it had a T connection that was capped off and a valve on that T, when I started turning the valve, water immediatly sprayed all over me (luckily it was cold ;-) so I assum that it is not air bound though I am not really positive.. I guess there could be air past the ciculating pump, but I would assume if the water made it to the pump, it would then be able to force the air out?

I didn't see any other vents in the system. Also don't see a gauge to measure PSI, but the rest of the house has about 25PSI water pressure... (I'm on the second floor condo, just above the garage where my water heater is).

No boiler that I know of, but the water heater is working fine. And yeah, i think it's the same that handles our shower/etc.

And put my hand on the circulator and it sounds/feels like it is running and that water is running though the pipes though again, since I have no way that I know of of turning off the fan seperately, it could just appear so due to the fans vibrations..

It worked last season, this is the first I turned it on this year. And i did have a new water heater installed about a month ago. The condo is about 7 years old.

ALH_4

photos

Digital pictures are worth a thousand words. A few photos of the piping on the water heater and at the fan coil would help a lot.

ALH_4

valve

Ok, I'm looking for the obvious first. Do I see a closed ball valve behind the expansion tank? It's a little hard to tell. The handle will be aligned with the pipe when the valve is open.

yish

The handle is right above the 4 inch duct work heading off to the right of the picture. You should be able to see the valve on the cold water (right) side just above the duct. It is set to open, and I am getting hot water to the shower/etc in the house.

BTW, thanks for taking the time to help

ALH_4

hmm

Isn't there another valve up by the ceiling? You might crack the chrome screw on the pump motor while it is running and see if air comes out.

Bob Forand

Can you tell whether there is "hot water" before and after the pump? It sounds as though the pump is bad if you are getting hot water at the shower.

yish

The pipe feels the same temperature on both, the one leading into the pump, the one exiting the pump, and the one after the radiator going back into the wall.

yish

RE: Hmm

What you see opened up is pretty much a self contained unit (sheet metal on all sides behind the insulation). I can't really, or at least easily get access to the pipes on the other side to see if there is a valve there..

Is it safe to turn the chrome screw while the pump is on? I am just worried about water spraying everywhere while the electricity is live to the area.

EBEBRATT-Ed

If the hot water heater was changed a month ago it is possible that air got in the heating loop at that time.Can you hook a hose to the valve that you got sprayed with and run it to a safe point and see if you eventually get hot water?? If you do that would indicate a circulator or air problem.

ED

ALH_4

air

It might drip, but nothing a small rag cant soak up. The fact that you can hear the pump running and water moving through the pipes makes me think it's air. The pump should be almost silent and very difficult to tell if it is running. Following ED's advice will certainly get the air out if you have a hose and a drain handy. Close the supply valve and then open the drain valve until you get only water. Then close the return valve and open the drain valve until you get only water. You may have to purge it both ways because the air could be in either pipe.

If it isn't air, then you will probably need a heating tech, because something must have gone wrong with the pump. As a side note, it also looks like your filter might be a little dirty?

yish

Thanks,

I did as you suggested and within 15 seconds I had hot water coming out of the hose. Both the in and out pipes going into the wall are now warm/hot, but not super hot as I would expect (i.e not at the same temperature as my shower when set to the hottest setting). So it sounds to me like either the pump is not working?! or there is air trapped in the system. How would i let the air escape? Wouldn't the fact that both the in and out pipes are hot indicate that I may have flushed the air out of the system by turning on the hose?

Maine Ken

You have an open system. One where you are drinking your heating water. There will always be air in your heating loop.

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yish

Since I only have 1 valve up there, I just opened that one (connected to the hose) and water did come out right away. I let it run for about a minute before I closed it. But things still don't seem to be fixed yet. I don't know how I can clear out the other pipe, any suggestions?

yish

Then... It's a pump problem?

So that would mean that the pump is not working correctly since air is expected? Any ideas how i can check?

Bob Forand

If you have hot water on either side, it seems to me a bad pump. Is the pump cartridge getting hot ?

yish

Fixed! Thanks everyone!

After flushing the system with the hose, I turned the system on but hit the switch the wrong way (I was standing on the ladder) and turned on the cool setting, as such the pump wasn't running so the pipes got cool again pretty quick. I just realized my mistake turned it on to heat and, heard the pump startup and almost instantly piping hot water was flowing through the whole system. I am now getting hot air in all my rooms and hopefully soon will be able to take off some of these layers. Thanks everyone, you were a ton of help and a great resource!

jim P._2

Mr. Yish, just a homeowner here keeping up with your posts and I must say all these profesionals went out of their way to help you at no cost. I hope I'm not out of line for saying this but if you arent in a bind please consider buying a brick to support this site. Its a great way to say thank you.
Even though they were subtle about it they mentioned that you are drinking your heating water. I would seriously consider changing that. Your health depends on it. Jim

yish

Thanks again and drinking water

Absolutely right. I really appreciate everyone's time and effort spent on helping me out! Purchasing a Brick was the least I could do :-).

About drinking the heating water, I am wondering why this is such a concern? I would think that the the way this system is setup, the water is going through copper piping just like everywhere else in the system... Yes, there is a circulating pump but that seems pretty common (i.e. if I had a recirculating line set up to my water heater). Just looking for more information to understand the severity.

P.S. I only drink the filtered water from the fridge, but am still considered with regards to using the water out of the tap for cooking and such.

ALH_4

hx

Mostly the danger is letting the water sit in the fan coil all summer and then pumping it into the water heater in the fall when you turn on the heat. Bacteria can grow in the stagnant water. Ideally your system would have a Flatplate heat exchanger separating the two. This would require an additional circulator and another expansion tank.

I dont mean to minimize the danger, but you probably aren't drinking or cooking with your hot water anyway and your system has a very small volume, probably not much more than would be sitting in the heat exchanger anyway. You might "exercise" the pump periodically during the summer to flush out the lines by turning on the heat for a few minutes. I assume your water heater is set relatively hot for heating purposes. 140F is generally considered hot enough to kill these bacteria though 140 is quite hot for un-tempered domestic hot water.

Kevin G_2

Heating pump

I would also check that the pump is a bronze pump not cast iron and suitable for domestic water. another little thing to check for safety.

Joannie_12

The Concern

Drinking the water is not the concern. Legionella bacteria grow in these types of systems, because the temperature is usually ideal, and because the water can just sit there for longish periods of time. The bacteria gets in your lungs through showers, etc., when it is aerated through our faucets.

You might want to do some research into Legionella. Or search this site for phrases like "Open System" or "Legionaires Disease" or "Legionella."

I hope this helps. At least one wonderful fellow who posts here has been bitten by this, and his descriptions of his ordeal were pretty wicked.