Problem with hot water


  #1  
Old 01-24-19, 05:24 AM
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Problem with hot water

Hi,

I have hydronic heating system with 10 zones. Yesterday one of the heating zones developed a leak and had to shut off the system quickly and close the valves for that system. The leak was at the radiator baseboard on the wall. After that I turned the system back on and it looks like all the heating zones are working.

The hot water zone doesn't work. The priority on the control is hot water. The green light is on. I can hear the circulating pump is working but the pipes that go to the water heater are cold.

I have a propane boiler and three temperature loops: high, medium and low.

Each zone circulating pump is connected to a thermostat, except zone 1.
The boiler cycles to maintain 180 deg F on the high temperature loop and all the loops are connected.

There is another circulating pump next to the water heater.

Please let me know if you have any questions about the system.
Any suggestions where to start?

Thank you.
 
  #2  
Old 01-24-19, 06:52 AM
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So are you saying zone 1 is the hot water zone and there are 2 pumps for zone 1 Ė and you can hear one of those 2 pumps running?
 
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Old 01-24-19, 07:27 AM
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Yes. Zone 1 (priority) is hot water. There is pump on the zone. It is working non stop for the last 8 hours. There is also a smaller pump close to the water tank. The secondary pump is connected to the control to 120 connections. It is not connected to a specific zone.
 
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Old 01-24-19, 07:34 AM
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Picture 1

Zone 1 pump (priority)

Picture 2

Zone 2 pump (next to water tank)

Picture 3

Control, Zone 1 green light

Picture 4

Control, 2nd regulator next to water tank, connected to 120 connections

Picture 5

Water tank with pump, this pump is connected to a white switch on the wall. The switch is on. You can see it in the picture.
 
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Last edited by kuzya; 01-24-19 at 08:34 AM.
  #5  
Old 01-24-19, 08:14 AM
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Those pictures are private until you allow them to be seen by the public.
You could post them to the board...... How-to-insert-pictures
 
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Old 01-24-19, 09:00 AM
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I inserted the pictures.
Thanks
 
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Old 01-24-19, 11:33 AM
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Iím no expert, but Iíll bet they will be along soon.

But it sounds like the circulator by the tank may not be running. I donít know why the other circulator would run continuously however. Maybe you could check out the circulator by the tank to see if you can hear it running. If not maybe you could use a multi-meter and see if you measure some voltage at the circulator by the tank.
 
  #8  
Old 01-24-19, 11:40 AM
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K,
Your hot water coil in the boilermate may have become air bound not allowing your water to circulate just as it would in a heating zone which in essence it's all it is.

If you could expand the pics to just the boilermate and the bottom connections. There should be a spigot connected to the heating coil. If you open that spigot and let the water drain until you get a clear stream of hot boiler water that may do it.

Do this with the system off, no pump running and that zone isolated.

Hope this helps a little.
 
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Old 01-24-19, 01:39 PM
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Pictures are upside down, not sure why. The picture on my computer looks good. It looks like the boiler supply is on the left and return is on the right. The middle is the cold water supply. Which one is the heating coil?

One more question. You said system should be off and that zone isolated. Does that mean I should close all the other zones off?

Thank you!!!!

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Last edited by PJmax; 01-28-19 at 12:01 PM. Reason: cropped/resized/reoriented pics
  #10  
Old 01-24-19, 03:30 PM
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hat spigot on boiler return is to bleed the coil of air. Just close the return valves so fresh water doesn't feed in to other zones and shut off power to system.

Open fast fill on feed valve if you have to build boiler pressure to 25 PSI and open spigot to remove air until straight water comes. If you can't find feed valve, there's not a lot of water in that coil so just open spigot and see if air is the problem.
 
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Old 01-26-19, 04:55 AM
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It worked but there is another issue

Thank you for all the help. There was a lot of air in the hot water loop and othet loops. I removed all the air. I also changed a leaking drain valve on the boiler.

I am having a different issue now. The boiler reaches the temperature 180 deg F and shuts off if I have 1 or 2 pumps running. If there are any other pumps running the temperature stays at 130. The boiler keeps heating but the temp doesn't go up. If I turn off all the thermostats the temperature goes back up.

Thank you!
 

Last edited by kuzya; 01-26-19 at 06:50 AM.
  #12  
Old 01-26-19, 08:53 AM
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K,
How big is your boiler and how much radiation is it heating. It sounds like your boiler is too small for your home.

Something simple to try is turning on 1 zone at a time and see how the boiler reacts.

A little more info on your emitters and boiler specs and pics would be helpful. Is this a new problem or on going.

Hope this helps a little.
 
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Old 01-28-19, 09:24 AM
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Getting info

I will get the info after work tonight. Thank you!
 
  #14  
Old 01-31-19, 03:38 AM
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Here is more information

Boiler: Teledyne Laars JVH160NCSS

Input rate: 160k btu
heating capacity: 131k btu

zones: I have three loops
hot med and cold.

hot loop - closest to the boiler, hot water and 2 water basebord loops for the in law appartment. Baseboards are above the floor on the wall.

medium loop(wood) - second from the boiler, master bedroom loop, two kids bedroom and bathroom loop, very large kitchen loop, study 3rd floor loop

cold loop (concrete) - bedroom downstairs loop, great room loop, bathroom and kitchen in law appartment loop.

There are two injection pumps connected to tekmar controls. The pumps inject hot water from hot to med and cold loops. It keeps the cold and med loops to the correct target temperature. There are outdoor, boiler and mix sensors for the two controls.

If I shut off all zonea the boiler reaches temperature. If a couple of smaller zones are open - the boiler reaches temperature. If one large zone with other zones are open the boiler will stay at 130 and not reach the temperature. It seems to be getting worse. This is a new issue.

I will post picures later today.

Thank you.
 
  #15  
Old 01-31-19, 01:32 PM
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If you are sure all the air is removed from the system and the boiler is obviously working and verifying the pumps are working it sounds like a water temp problem. If only the med & cold zones are effected and this is a new problem I would look at the tekmar possibly not adjusting water temps for the colder weater.

Did you feel the pipes of the questionable zones at the heaters to see what temp the pipes are. It could be the supply water temp is just not enough going to the emitters in this extreme cold snap we're having.

You've go a lot going on there and without being there is difficult to see what is happening. Can you override the tekmar to send unmixed hot water to those zones to see the difference.

You described the loops but how much total baseboard is on each loop. Is that leak fixed and back on line. Basically without being there to see the system design and other variables it sounds like you have to much radiation for the boiler or the tekmar may be either malfunctioning or set to low.

You have a lot of sensors there and any one of them can be trouble.

Did you try running the cold zone by itself and see if it keeps up. That 1 zone alone shouldn't be too much to heat. If you still have trouble I would look at the tekmar and sensors.
 
  #16  
Old 02-01-19, 07:59 AM
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Ok.

I spent the whole day yesterday trying to figure it out. The one zone with the leak is fixed. I replaced the 3/8 inch copper tube inside this metal plate with channels for the pipe. Very strange size for the tubing. Found it in one store in my area. Nobody has 3/8 solid.

Here is what I did yesterday. I verified that all the sensors for the mixing controls are working. The controls do turn on the two mixing pumps. I can hear the pumps. The temperature increases in the medium and cold loops. All the pumps are working.

I decided to clean the boiler yesterday. It has a interesting heat exchanger.
I took everything apart. There was a lot of rust on the burners. A lot of packed material (soot?) in the fins on the top of the boiler. I vacuumed all the soot out and
cleaned all the rust off. Put everything back together. Turned and same thing.

If I partially shut off the valves for each zone the boiler is keeping up the temperature in each zone and eventually cycles off, temperature drops and turns back on. If there is a lot of demand the temperature drops to 120 and doesn't go up while the boiler is working, when this happens the controls turn on the mixing pumps and it stays at 120.

Temperature at all the supply lines is good when the boiler can reach 180 deg.
If I run one or two zones the boiler can reach 180 deg.

I can only measure how much baseboard I have in two zones. The rest of the zones are under wood or concrete.

I don't think there is any air in the system because all the zones are working independently but not together.

One more thing when I cleaned the heat exchanger one of the tubes was bent, it was touching the fins on the other tube.
 

Last edited by kuzya; 02-01-19 at 10:19 AM.
  #17  
Old 02-01-19, 11:22 AM
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You did not mention if you tried to run the cold zone by itself to see what happens.

When you say cement and wood do you mean you have radiant heat. If so that is low temp heating and everything depends on the design.

By partially closing the valves you are just slowing the flow of water to the loops, and the boiler keeps up. That is showing you the boiler cannot keep up with the demand with the valves fully open.

You may have to get someone experienced to physically see exactly what you have. With everything you have described for some reason your boiler cannot keep up with the demand.

Have you ever had this trouble in the past.
 
 

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