All I Want for Christmas: Hot Water!!

[JBTKO]

Good Evening! First post ... My family is going on week two without hot water and living on the mercy of the YMCA for showers and boiling water for the rest. Here's the scoop, praying someone has a magic answer:

We have a Slant Fin Boiler hooked to an Amtrol Boiler Mate tank. There are six zones connected in total to the boiler. When we first lost hot water we brought a plumber in who told us that we either needed a new water tank (gunked up coil, or bad thermostat), or there was an airlock he could not get passed. He also suggested getting a second opinion. Needless to say, I'm not sure the cost to have him come out was worth it. However, after the second opinion thought it was either the thermostat, or needing a new tank as well, we tried both. He first installed a new thermostat with no success in getting hot water. Then we bought a new tank (NOT cheap at 40+ gallons). After that installed we had warm water, but not hot. He then believed the issue to be a clogged zone valve. Another $100+ later, that valve is replaced. We had hot water for a bit, however it has gone back to just luke warm. The boiler supply line is super hot, however the hot water outlet and boiler return lines are both just warm. All other zones seem to be working perfectly fine. We're bleeding money at this point (just in time for Christmas!!), and are honestly so over the whole thing. However, we're also out of ideas. Any advice from seasoned plumbers that might know more than our locals? Please let me know what other information and/or pics might help!! Thank you so much in advance!!

 

[Reach4]

I don't know the answers, but a photo or two often helps people picture your system better.

 

[Sponsor]

 

[WorthFlorida]

Good Evening! ......The boiler supply line is super hot, however the hot water outlet and boiler return lines are both just warm. All other zones seem to be working perfectly fine. ....!!

The problem is only hot domestic water, the heating side is OK? What is between the supply line & the hot water outlet? Just the boiler and the boilermate tank? A picture of the plumbing between the two would be helpful. Was the thermostat explained above for the mate tank? Is the circulator for the mate tank working? May have an air block.

 

[JBTKO]

I was worried about an air block :/ All other zones are working, is there a way to tell for certain if that is the issue? Is that an easy fix? Let me know if other pics are needed! Thank you again!!

 

[Jadnashua]

First, simple thing, but make sure the the thermocouple sensing the tank's water is fully inserted in the well and that the thing is connected properly. On most of them, you can test the thermocouple if you have a multimeter. Remove the two leads, measure the resistance and note the temperature. The resistance changes with temperature. THere should be a chart in the manual that describes the resistance at certain temperatures. You can put the thermocouple in a pot of hot water to vary the temp.

The pipe to the indirect should be hot when it is calling for heat. After a bit, the return line will heat up as well. If neither is happening, then I'd suspect the pump or the logic that controls it. You could measure the voltage to the circulating pump to the indirect. If it's there, and the pump's not turning, the pump is dead, if it is not there, the problem is further back towards the zone controller. If the pump is turning, but there's no flow, it could be an air lock or the impeller is shot. If they did things well, there should be a drain valve to help purge that air. FWIW, if there are any shutoff valves in the supply/return lines, make sure that those are open! If they happened to use a gate valve, and the gate broke off of the stem, it can look good, but the gate is restricting the flow. Ball valves tend to work better, longer.

While you may not be able to fix it, it can help if you read the theory of operation that is in many of the manuals provided with the system. Logic should help you isolate where the problem is.