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Poor hot water / heating performance

I purchased a townhome with a hydronic heating system and it has never been a good performer if the temp dips below 40º outside (happens a lot in WA).  I've had a couple of people come out over the last couple of years, look at the system and tell me things seemed to be working OK.  I'd begun to chalk it up as a poor system choice for the layout of the house.

I'm new to this and the builder left ZERO information on the system or the requirements used to design it.  The system uses a water heater running the hot water through a recirc pump / aquastat (Armstrong 25BU) and plastic tubes to four zones in the house (living room, kitchen, and the two bedrooms).  Each zone has an in-wall fan controlled by its own thermostat (heat radiates from the coil with or without the fan blowing air into the room).  That, unfortunately, is all I've been able to find about the system.

Lately, performance seems to be even worse.  The water out of the faucets in the house is hot enough, but it takes a while to get that way.  It is currently in the 50s in the lowest floor of the house.  Warm-ish air is blowing out of the fan downstairs.

A plumber came by last week and said he thought the recirc pump impeller was shot and needed replacement, to the tune of $1000.  I held off because, in my mind, even when we moved in the system wasn't doing all that well... so perhaps a more capable pump would help (instead of a direct replacement).

So, I started trying to do some research to understand the requirements of the system and whether or not a more capable pump would help, but the builder has been completely unresponsive, so it looks like I have to do this on my own.

Is anyone out there able/willing to walk a newbie through this?  Just let me know if there's any other information I can provide and I'll pass it along if I can get it.

Thanks in advance!



  • icesailoricesailor Posts: 7,265Member
    HW performance:

    We're not supposed to discuss pricing here.

    $1000.00 seems a little high to me but I don't know your situation.

    It's possible that there is something wrong with the circulator.

    IMHO, this is a really poor way to heat a home and make hot water. If the hot water is OK but the heat isn't hot enough, either your heat emitters are too small or your water isn't hot enough. Also, after this time, the coils of your heat emitting units could be fouled because it sounds like you are using potable water to heat your house. A very bad idea.

    Get a digital infra red thermometer and check the temperatures coming out and going back to the water heater. See if your domestic hot water temp. is the same. The heating water should be hotter. If everyone in the development has the same problem, you have  a design problem and will need study to correct. Take some pictures of what you have and post them back here so we can see what you have and take it apart.

    We like pictures.
  • billtwocasebilltwocase Posts: 2,385Member
    yes pics

    something is either poorly designed, or your area lacks knowledgeable techs. Was the impeller shot? I always have a hard time fathoming a customer paying for a "professional's" schooling. How old is the townhouse?
  • J_FIGJ_FIG Posts: 5Member
    Reply w/ first pic

    Thanks for the quick responses!  I didn't intend to spark any debate on price, just wanted to illustrate the motivation behind understanding the system better before blindly throwing money at it...

    I haven't had the pump replaced or anything yet.  The townhouse is 4 yrs old so this is all builder-installed.

    Pics-wise, let's start with the attached.  Recirc pump (Armstrong 25BU) and timer on the left, with the two light red lines leading to the gas water heater (to the left, out of the shot).  The four pairs of bright red tubes carry the water to and from the four zones I mentioned before.  Flow to each zone is controlled by the little red caps, just below the circular zone labels on the top (return) line to the water heater.

    Note the gauges at the bottom reflecting GPM to each zone.  The little red ring floats top to bottom (bottomed out = 0 GPM to that zone).  No matter what I do to the red caps, the two left-hand lines (2nd bedroom and kitchen) don't budge from zero.  The outgoing lines to those zones are hot, but the returns are cold.

    Thanks again!  Let me know what else I can provide (info/pictures/whatever).
  • RobbieDoRobbieDo Posts: 131Member
    What Temp

    What is the water heater temp set at? Is this water heater also used for your domestic water? Is there a expansion tank, air scoop, air vents? Need some more pics of the complete system to try and help you.
  • J_FIGJ_FIG Posts: 5Member

    Yes, one source for heat and domestic water.  See attached for my attempt at a simple layout/description.  Hopefully this helps...

  • RobbieDoRobbieDo Posts: 131Member

    The drawing is ok, but pics would be a lot better for us to help you. Expansion tank, air vents, pumps, valves etc. Thanks
  • J_FIGJ_FIG Posts: 5Member

    I went with a diagram because it's tough to take decent pictures in that space. Here are a couple of views, one of the expansion tank and one of the top of the water heater with the air inlet/exhaust and the Honeywell AM-1 series mixing valve.

    If there's something specific you're looking for out of the pictures I can try my best to capture those, just let me know what you can use.

  • RobbieDoRobbieDo Posts: 131Member
    Where I live

    I can not install a system like that. Looks like your using potable, no air vent. Not sure what else to tell ya, I would never install a system like that. Maybe someone else here would like to chime in??
  • billtwocasebilltwocase Posts: 2,385Member
    thanks for the pics

    unfortunately all I can say is what the hell is that? That would not fly around here either
  • RobbieDoRobbieDo Posts: 131Member

    You said that you recently purchased the town house? Did you have a home inspection done, I know some banks require that prior to giving money? I'm surprised someone said they would change the pump, I wouldn't touch that system, if it was me.
  • J_FIGJ_FIG Posts: 5Member

    Yes, inspection was done prior to purchase.

    A little confused by the comment on not having any venting - are you talking about something other than the big inlet and exhaust tubes coming out the top of the water heater?  Again, I'm still just learning about this stuff so I apologize for the silly questions.

    Other than letting me know the system sucks (which I already knew), can y'all tell me more specifically what I should be seeing here that's missing?  What is it that alarms you?
  • RobbieDoRobbieDo Posts: 131Member
    Call A PRO

    You need to have a Pro come out and look at the system. Where I live, upstate NY we can not put a system in like that, codes. Using potable water is not good for a heating system, no air vents, umm and a lot more issues here. If it was me, you called my company to look at it I wouldn't work on it. I would install a system that will work properly and efficiently. I'm not sure what else to tell ya, call a pro and get it done right, the investment is worth it, now and in the future it will pay off.
  • HenryHenry Posts: 821Member

    Those tank connections look like flexible gas connectors! Yeeks! The whole job looks like an amateur carpenter put it together. It is time to get a pro involved, sue the inspector and the seller!

This discussion has been closed.


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