Hot Water Furnace Short Cycles after some water removed

John Taylor

Sleeby,

I might suggest that you have a professional look over your system. This should be done once a year regardless of a noticable problem or not. A good inspection by a qualified technician will keep you and yours out of harms way and insure that the boiler is operating safetly and efficiently. At that time have them explain the basics with regard to your system so that you can understand it's operation and maintain it between visits. The "Find a Professional" part of this website will help you find someone in your area.

Better safe than sorry.

John Taylor

Custom Climate Systems, Inc.

Dexter, Michigan

Sleeby

Hot Water Furnace Short Cycles After Some Water Removed

Hello,

I ignorantly drained a cup or so of hot water from each of three spigots in my utility closet around my furnace (I was trying to solder a shutoff valve on a faucet hot water line and couldn't figure out how to drain the lines. . .another story but with a good ending). Anyhow, two of the spigots drained hot dirty water and one hot clean looking water.

This was on Sunday. Since then, the furnace has been short cycling (3 minutes on or less at a time) and the house temp never exceeds 65F or so regardless of the thermostat setting.

This is a gas furnace with an expansion tank which heats baseboard convectors around the house.

What did I do and how can I most easily fix it?

Thanks for your time and for any advice you may have for me. :-)

Sleeby

or. . .I may have closed a valve in the water line

I cannot remember for certain. There is one valve in the boiler's water line which is currently closed - I may have closed it when trying to figure out the hot water pipes last weekend on another project but I am not certain - I should really take better notes when doing these things.

When I just opened it now I could hear water begin to flow and then it started making bubbly (lack of a better word) sounds within the pipes. I turned it off again in fear of causing problems or worse. I beleive that the water I am letting in by opening the valve is cold and that it is entering into the hotter pipes - this is only from feeling the pipe's exteriors.

I realize that from just text you cannot probably help me but can anyone answer these two questions for me?

1) Does the boiler need a constant water supply such as, perhaps, from this pipe I have which is closed? Or is it a closed system where it does not need a supply of new water during normal operation (IE - other than when filling)?

2) Is it dangerous for me to open this valve and let the water flow through it? Hard to answer with so little info I know. Could the short cycles I'm getting be from my having closed the valve and denied water to the boiler - causing it to overheat only a minute or three after kicking on? The furnace cycles on every 5 or 6 minutes such that if this were the problem it would always be in a state of overheating I reckon. I do not wish to kill myself this week. Heh.

Weezbo

Dude! I like You and dont even know you *~/:)

You right ! Maybe hang out on terra firrma a while longer:) Great idea.! <+:) i know the Pope , he assures me of this:) here is what you can do this is sorta simple. turn the boiler off. find the gauge that says temperature pressure on the boiler. write down the numbers on a piece of paper ...go make a cup of coffee.....burn some daylight till it seems like maybe its cooling off kinda heavy.Oh By the way...We have the boiler turned off so beat it back to the boiler and check the temps and pressure on the guage again ok if the temps say around 100 degrees YOU in business:) go over to that valve you noticed was making the bubbly noises and crack it a bit so water rolls into the pipe check the pressure again watch it for a few mins..is it going Higher? ok! You really lucky when you see the magic number 20 roll up shut the thing off:) now turn the boiler back on. oki. when the temp goes up to 110 turn it back off for a second....what is the magic number on the pressure gauge now? it should have gone up a bit...leave the boiler off for a couple mins is the temp and pressure both going up? If so you got it justabout made in the shade. do you have zone valves on the boiler? do you know how to manually open them? do so.didthe pressure drop way off again? no problem...........open the valve and let in some more water till it goes up to 18 this time:)turn it back off. turn on the boiler again...........let it run up to 140F andturn it off what is the pressure reading? is it like 23psi? go turn all the termostats you have up to 90 and come back close all the zone valves crank the boiler back up.......... there is a safety relife valve what you are going to do now is test it get a small plastic container like small soap bucket or 1/2 gallon of milk somesorta container the pipe you want to set it under comes down from the safety relife valve ...now pull the lever up woosh hot water and steam and what not is coming out:)it should stop leaking pretty quick...check the temp and pressure now. ok now you have some heat and it should be circulating, soon all the pipes leaving the boiler will be hot the cold side returning will at first be cold un til it makes its circuit....soon as it comes back hot go turn the thermostat all the way down on that loop.(zone)do that on each zone...if one of them wont come back hot...shut the boiler off open that zone valve ,go get a cup of coffee and burn some more daylight...all you want to do is put more water into the boiler again. so what ever the pressure is its going up and its going into that one and only zone...by now the boilers bringing the water up pretty fast and will circulate through that zone first..soon as it does go turn the other zones up to like 70 F and leave it alone...now ...if the heat isnt comming up pretty quick say an hour then you probably have no spirovent and have to find some bleeder valves to open, some people call them coin valves(vents). ok so now you got to go check the boiler pressure again.:) Or You could call a guy to come over and he would do something similar unless he had a wayne pump and your system had plenty purge valves(boiler drain valves).....*~/:)