boiler not working right

crazy charlie

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I have a 12 year old standard house oil boiler,Weil Mclean.I have plenty of hot water,cycles on and off perfectly.When the thermostat in my house is set down at night,a small flow of hot water still goes through the baseboard,and when i tried to turn the thermostat up this morning the circulator pump did not go on.So when i dont want heat I still get a little without the circulator pump going on and with the thermostat all the way down.I turn the thermostat up and the circulator usually goes on and now it does not.Thank God it is not too cold out because there is not enough heat.Any ideas before I call the boiler man????Charlie
 

SS MAYFLOAT

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Re: boiler not working right

Hi Crazy Charlie, If your thermostat is calling for heat, check your voltage going to your circ pump. Your pump could also be seized. Does it hum or sound like its running? How old is the pump? Hot water tends to be acidic. After a period of time the impeller tends to rust out. This can stop the pump. Natural convection or consumption useage maybe occuring giving you some flow.<br /><br />If the pump motor is cold to the touch and is not running, then there should be a relay that turns the pump on. Usually there is a controler that kicks the pump on that has the relay built in. Older units could have a seperate relay that could be bad.<br /><br />Just some thoughts without seeing what you have.<br /><br />SS
 

crazy charlie

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Re: boiler not working right

Thanks for the reply SS Mayfloat.The entire set up was new about 12-13 years ago.The circulator is not humming and I will check if it is warm and I will look for a relay.The mercury switch in the thermostat sparks going to the lower temp but doesnot going to the higher temp.Last winter I had 1 time where the heat went on and would not stop circulating.I will take a closer look tonight when I get home.Thanks again and I welcome any suggestions.Charlie
 

radar750

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Re: boiler not working right

CC how many thermostats (zones) do you have?<br />If you have more than one zone and only 1 pump you have to have zone valve controls. If one is stuck open a little and not closing than hot water will get by and find its way up on gravity giving you a little heat when you dont want it. If stuck it also cant open completly which trips an end switch calling on the pump. If your other zones work fine it is probably the zone valve head<br />which is an easy fix, they sell them at home depot.If you have a pump for each zone like SS says you will have a reley for each pump.Try standing down right next to the boiler and have someone turn the thermostat up and down and keep repeating this and listen for a click of the reley pulling in, this will confirm the thermostat<br />signal is reaching the control,if you hear no click the T-stat or wire connection to the boiler may be bad. If you have a click you or a tech will have to determine if there is power to the pump. If you have power to the pump and it is not working you need a pump,it you havr power in to the reley and no power out,it is the reley. There is a flow control valve on the near boiler piping called a flowcheck that is there to prevent hot water from passing when not calling for heat in that zone,if that is bad you will get heat by when you dont want it.There is pressure and hot water behind flow check valves and some zone valves so be careful if you try to replace anything. Some zone valve heads just twist off or have a couple of screws and you dont have to open the system to change them just be careful.
 

JGREGORY

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Re: boiler not working right

Crazy charlie, Not that this may help you seem to be getting good advice from SS. Last year my 3 yr old systems relay went bad darn thing never shut down. Thought it was the thermostat at first put in one of those programable ones finally had to call for service. Bad Rely. Go figure :rolleyes:
 

SS MAYFLOAT

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Re: boiler not working right

Crazy, If you are seeing sparks within the mercury switch, then you have the low voltage output calling for the heat. With you saying your boiler is cycling like it is surpose to tells me that function is working properly. Radar 750 did bring up a good point. Do you have zone controls? With that age of a unit, some have them and some don't. Do you have a t-stat in each room, or just one centrally located.<br /><br />I usually work on large commercial systems, but they all have the same safties and functions. Does this system also supply your house with hot water eliminating the need for a hot water tank?<br /><br />If I was there, I would unhook the circ pump, and wire it into an extension cord providing it is standard 110volt house current. If it runs, then it is a relay. The relay can be an external, on an internal relay that would be located in the controller. <br /><br />Do you have a voltmeter and know how to use it?<br /><br />SS
 

crazy charlie

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Re: boiler not working right

Thanks again guys!!!!I am getting better info here than for my boating issues.I have 2 thermostats and 1 small green circulator.I think it reads cartridge pump???I took a small cover off the pump last night and saw what looked like a fuse with wires connected to it.It was a little smaller than a roll of nickles.All I could do is tighten the connections.When I turn the thermostat up there is no spark in the merc switch but there is spark when I turn it down.Any way last night it decided to work all b yitself.I heard the circ. go on in the middle of the night. So now I am really confused.Charlie
 

crazy charlie

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Re: boiler not working right

The system did the same thing last winter,and also began working by itself shortly after.I had a boiler mech come to check it but it began working before he got to my house so he could not determine what to fix.He replaced a feeder valve which comes off the house water supply,and into the boiler.I was convinced he didnt narrow anything down,he just replaced it because he had one with him.I assume now that I was correct.By the way I dont have an external hot water heater.Thanks again guys,I am all ears as to what to replace first.Charlie
 

SS MAYFLOAT

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Re: boiler not working right

Charlie, with it being intermittent like it is, most likely it is the relay. The relay's contacts are getting pitted and corroded. This is what causes it to work and not work. You need to find the control relay that kicks your circ pump on and off, and change it out. If it is a typical relay with a 24volt coil, it should be less than 10 bucks.<br /><br />SS
 

crazy charlie

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Re: boiler not working right

Any idea what the relay may look like????I know sunbrella fabric way better than I know my boiler.Charlie
 

SS MAYFLOAT

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Re: boiler not working right

Relays come in all shapes and sizes. Most are square rectangular shaped. Some have clear covers with terminals sticking out of the top, some plug into a socket. <br />Not seeing what you have is almost impossible to describe. Is their a blue box on your boiler? Does it say Honeywell on it? It should be about 5 or 6 inch square with a reset on it?<br /><br />Another way of finding the relay is to follow the wires from the circ pump back to the relay. If the wires go to the box I was describing, then it is an internal relay built into the controller. It will probably need changed.
 

crazy charlie

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Re: boiler not working right

The box that says honeywell with the red button id the boiler reset.I replaced it last year.It sits on the top of the burner itself.There is no blue box.I will follow the leads from the circ and see where they go.Any chance it is under the cover of the circulator???I opened the cover and saw something the shape of a roll of nickels with wires coming out of the ends.There are also 2 boxes on the top of what looks like the main flow valve .They are each mounted on a pipe that comes out of the main valve.They have a small slide arm sticking out of the bottom of each.It looks like an adjustment arm.Thanks for taking the time with me.Charlie
 

SS MAYFLOAT

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Re: boiler not working right

Charlie,<br /><br />You should have a box that says zone controller on it. If you can get me a model number it would help me in locating some info on your unit.<br /><br />A buddy of mine has some manuals on weil mclain units. Been confiring with him on this to.<br /><br />SS
 

radar750

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Re: boiler not working right

CC If you have 2 thermostats and only 1 pump like you say than you have to have zone valves. your pump is a taco 007 or 0010, the fuse like thing you saw is actully a start capacitor for the motor. If you follow your piping off the top of the boiler you should see 2 small motorized valves with wires going to them, they are probably 3 wire Taco5550 and might have a green or gold head, the head is the part where the wires are connected to.There are other types of zone valves,honeywell makes a 5 wire zone valve but Taco are the most common. Those valves have a very small 24vac motor that pushes down on a plunger to open them on a call for heat.The small arm you see is a lever to open the valves manually,if the arm moves up and down very easy than the valve is already open,if it moves up and down with a little force them you are opening manually, if it moves very hard than it is sticking and the little motor in it will not be able to open it on its own and it should be replaced.They can be stuck open,closed,or half way. They also can burn out if they stick very bad or are powered by a weak transformer which you can test buy finding it and putting a meter accross the terminals you should get at least 24vac with a full load when both thermostats turned up.I like to see 1 transformer for each zone valve,it is a little overkill but thy last longer that way.Ok back to your pump,did or can you test it for power to it,again,put a meter accross the 2 incomming wires look for 120vac. If you have power to it and it is not running,change the pump, those pumps can be very quite so listen very carefully.Just another thought we could be overlooking something very simple, your system could just be air bound and need to be purged.<br />Ok if you would check the following for me maybe we can narrow this down<br />1. turn up both thermostats,wait 5 minutes and check to see if the little arms slide very easy or not, this will tell us if the zone valves are at least opening.<br />2. check to see if you think the pump is running,can you hear it.<br />3. is the piping going away from the zone valves getting hot,if so see how far down piping is hot.Also is piping above the pump hot if so how far?<br />This will tell us if ther is any water moving through the pipes<br />You said the boiler it self is running ok and I guess you have a tankless coil for your domestic hot water.so that tells us it is working and now all we have to do is get your water pumpimg.
 

crazy charlie

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Re: boiler not working right

Thanks again SS Mayfloat and Radar!!!!I will look for the model # and post.The circ has decided to keep working the way it was supposed to .I hate when things seem to fix themselves,it makes it harder to troubleshoot them.I will turn up the stats and check the operation of the valves.I know how to bleed the system so I will do that too.It is comforting to know that there are people who care in this forum.Thanks again guys.Glad to here you got the pooch back.Time to put a chip in him just in case.Charlie
 

crazy charlie

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Re: boiler not working right

I am back again.After the circ worked fine for a day and a half,it did not go on again this morning,but decided to start working just before I left the house.Here is what i have:Radar was right --007 Taco circ,green Taco air scoop with air vent on top and 2 honeywell "syncron" with silver heads also on top (I think this is what you were asking me about ,zone valve??),beckett burner,Dual aquastat coming from coil going to transformer,a basler be18140pae 115v 50/60hz black white 24v 40va transformer.SS Mayfloat,I dont know if any of this is a zone controller none of the parts said that.Anyway,I checked the voltage from the transformer to the circ with the thermostat on but it was not going on it read .024 When the circ went on I checked the volts again and the reading was a bit erratic it fluctuated from .084 al the way up to 1.18.Does this mean i should try changing the transformer????The zone valve??leading to the upstairs seems to be in the open position just about always.the pipes are always hot.the other is cold and the lever operates the way it should as Radar described.Is this easy to change???Charlie
 

radar750

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Re: boiler not working right

CC<br />Ok it appears you have Honeywell zone valves, odd to have with everything else taco but it really does not matter. They should have 5 wires unless they are a really odd model,the 3 wires together power the valve open and closed, the other 2 are the end switch. I will give you sequence of operation.<br />1 T-stat calles for heat sending 24 vac to ZV<br />2 Zv opens and the end switch makes sending 24vac to a reley that turns on the pump.<br />3 the reverse happens when the temp on t-stat comes up to desired temp.<br /><br />You say your pump comes on and off, it could be the control or ZV shutting it off or it could run and get hot, shut off on thermal, cool down and repeat.My guess is that a control or ZV is shutting it down.<br /><br />Some of the newer Honeywell zone valve heads can be replaced with just 2 screws and swapping the wires terminal for terminal. Look on top of the valve for a place to insert a screwdriver,if it is a replacable head the 2 screws will be diagonaly opposite end to end, not 2 on the same end or same side they MUST be diag. Do not undo all four screws or you will have water everywhere<br />The older valve heads are not replacable without draining the pipes and then you should replace the whole valve body and head.<br />I will try to be very simple since it has been a long time since I have actully worked on this stuff. If you are not sure which zone valve heads you have Be careful since if you unscrew the older type you can have a big water leak, they just have 4 screws you can get at them all.The new ones still have 4 screws but I THINK you can only get at undo the 2 opp diag ends which will losen the head off to expose the last 2 screws which you DO NOT want to take off. I hope you are not totally confused by my explanation. You may be able to get a replacement at home depot or a plumbing heating supply house.
 

crazy charlie

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Re: boiler not working right

Thanks again Radar!!You made it simple enough even for a know nothing like me to understand.I hope I am lucky enough to have the one that is easy to replace.I do remember seeing about 5 wires so I may have the newer type.To tell you the truth I usually dont have luck when it comes to doing anything the easy way so I hope I have the right one but I wont expect it.I will make serious note of where the screws are placed.I play basketball tonight after work and i bowl tomorrow night after work so I hope i get a chance to get this done.Fortunately today it decided to work fine.If i have to drain the system to change the zv should I leave it to a pro to do.Should i replace the tank and the air valve,I saw thm at the home depot and figure I may as well replace them if they will have to be replaced sooner or later anyway.Thanks again,I will post results,keep an eye out.Charlie
 

crazy charlie

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Re: boiler not working right

My luck is just as i expected.I have 4 screws on the zv.so I guess I have to drain system.It looks like There is no soldering involved so it may be something I can tackle.Charlie
 

SS MAYFLOAT

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Re: boiler not working right

Sorry to leave you hangin Charlie. Been busy working and not much time fer myself the last several days.<br /><br />Sounds like Radar knows your system and sounds like your in good hands with his information.<br /><br />Good Luck finding the problem .....SS
 
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