Tuesday, October 25, 2011

What makes our thermostat click on and off continuously?

We have a 100 year old house. We had a new electric heating/cooling unit installed in the attic for our upstairs 4 years ago, and downstairs has the original gas furnace.

We have had several problems, seems I call the repairman every year for something. Our thermostat keeps clicking on and off, like doesn't even run a second and shuts off, clicks on again over and over. We just turned it off, and dh bougt a new thermostat and changed the air filter. Was fine for a while and then started up again. We've called the repairman for this in the past but I don't remember what they did/said. We've had three different thermostats now, don't think that's the problem??
What makes our thermostat click on and off continuously?
It sounds as if the fan kicks on and off quickly for no reason. There are two possibilites for this:



1. An intermittent short in the wire between red and green. This can be a real hassle to track down. Ohm out the wiring and check.



2. A fault in the printed circut board that runs the fan. On many of these relays are normally closed. This means that they have to power up to keep the fan off. If the board has a micro crack in it, when cold the fan will on and off for just a second or two. After the unit is warm, it won't do it anymore. It can be maddening because it usually happens at night or in the early morning.



Hope this helps.



Former lead tech in a very large HVAC firm.
What makes our thermostat click on and off continuously?
Are there air currents or drafts hitting the thermostat to freak it out? LOL :)
your temp in the house Drops Below the set degree in your House thats why it Keeps Coming On
You obviously have a draft or a cold air leak near your thermostat . A thermostat regulates the temperature,and when you set the thermostat at 68 for example,if the air around the thermostat gets cold it will click on again.

I would check for any open cold drafts in the house and insulate it good for the upcoming winter .
I had same problem,even if you clean your filter

every week, there is still dirt built up in motor

the repair guy, said they need to be cleaned once a year.there could also be a short in the compressor. I am sorry but looks like you call repair man again. good luck
Change the location of the thermostat with the aid of a specialist.

Heater Gauge in my 91 Acura Legend says engine overheating but Engine is cool! changed Thermostat & Water Hose?

The heater gauge says the engine is way hot but I can touch the engine with my hands. The upper water hose busted and replaced it. Lower Water hose doesn't heat up at all. Replaced thermostat. Still no change also the car heater only works randomly. Radiator is bubbling hot, when I open the cap the Antifreeze bubbles and overflows. Stil the engine is at operating temperature not overheating. What could be my problem? do I have a blown head gasket? or do I have a radiator problem? please help!
Heater Gauge in my 91 Acura Legend says engine overheating but Engine is cool! changed Thermostat %26amp; Water Hose?
It is definitely the water pump.

At the first part of the question, I thought of the temp. sending unit, but after I read the radiator is bubbling hot but the upper hose busting and the lower hose not getting hot, that tells me that there is no coolant circulating although the thermostat opens.

Replace the water pump before you do cause a head gasket leak. You will overheat the engine and possibly warp the heads.

REPLACE THE WATER PUMP!
Heater Gauge in my 91 Acura Legend says engine overheating but Engine is cool! changed Thermostat %26amp; Water Hose?
You probably have a dead water pump.
Sorry Bud, Bubbling antifreeze should be head gasket. Does the exhaust smell sweet and or white smoke? The head gasket will go out when you have an over heat situation like the rad hose busting on you.

How do i change the thermostat on a 1998 Cadillac Catera?

Find a library that carries the ALLDATA data base. They have a very good description of the technique involved. You will have to remove the upper intake manifold. This also requires the separation of fuel injection fuel lines. By the way, this is really an Opel/Saab V6, if you didn't know. Perhaps all you really need is flush and fill of the coolant. DON%26quot;T use the GM dexcool, use the Saab coolant or Ford Yellow coolant. SEE the %26quot;dexcoolsettlement%26quot; web-site and the other %26quot;GM Litigation%26quot; web-sites. Good luck!!
How do i change the thermostat on a 1998 Cadillac Catera?
Look in the book. Do what it says. You can find Chiltons Auto Repair manuals at the public library. It's not enough to say, %26quot;Take out the old thermostat and put a new one in and replace the gasket%26quot;. The pictures in the maual can better show you where the parts are than for you to be told to look here and there.

My oil pressure warning light on my Honda Accord 96 goes on when the engine is idle, what is the problem?

I have an accord 96 that has 100,000kms on it. had an oil change recently.



A few days after this oil change, I had an overheat and after this overheat, the oil pressure warning light started acting eratically.



First, after a cold start, the light does not turn on but after the engine warms up, the light flashes. The problem is, while revving the engine, the light goes off and immediately goes on again when the engine is idle.



To address my original problem, mechanics informed me that they would change the oil sending unit, change thermostat valve and thermostat switch.



After this, the problem was still the same (light goes off with revving). They recommended a general overhaul for the reason that the engine had so much sludge and they blamed the problem on the engine flush that was included during the change oil.



Now, i really dont know what to do next. General overhaul is too expensive for my budget.. Any tips?

Thanks very much!
My oil pressure warning light on my Honda Accord 96 goes on when the engine is idle, what is the problem?
the first and obvious question is--have you checked the oil level recently? I've seen drain bolts leak on Hondas if you don't change the washer for the plug and you could legitimately have a low oil condition. so thats the first thing to do.



then, if the oil is full, have your technician put an oil pressure gauge on the car to run a pressure test. That will tell you if the problem is a mechanical one (oil pump) or an electrical one (sending unit/gauge). Your description sounds like a mechanical problem with the oil pump. If the car does have low oil pressure, then the next thing to do is to have the oil pan removed to check the oil pick up for the oil pump. If it is clogged they can clean it. If not, then you'll have to change the pump.



accords are not known to generate a lot of sludge unless the oil is never changed. the engine flushes rarely provide any value.



hope that helps
My oil pressure warning light on my Honda Accord 96 goes on when the engine is idle, what is the problem?
Your oil pump is going bad. what is happening it is not pumping enough oil at idle and triggering your light. an easy way to check is get an oil pressure gauge, hook it up at make sure, this can have disasterous effects on your engine if not taken care of IMMEDIETLY.
Honda's are not known for sludge unless you don't change the oil at all.

Does the car have oil in it?

Could be the pump going bad...or the sending unit may not be reading correctly...or as simple as it wasn't wired correctly.

We had one that was triggered by the e-brake and just had to rewire it.

Sounds like the oil pump though and if it is and its not fixed its a good way to blow up a motor when it eventually freezes up.

My 2000 Cadillac Deville northstar motor is overheating and loosing coolant. I've changed thermostat twice?

The 1st time I changed the thermostat and added coolant, it didn't overheat for approx. 2 weeks. Then I had to put another thermostat in(thought this one didnt work) and put the cooldex antifreeze in as manual requested %26amp; it didn't overheat for another 2 weeks. Now nothing is working and I can't drive it from frequent overheating, Can someone help me and let me know what could be wrong with my car??
My 2000 Cadillac Deville northstar motor is overheating and loosing coolant. I've changed thermostat twice?
Best thing to do is to have the coolant system pressure tested,as well as the cap.The majority of the time it can be found that way.After the pressure test,If a leak is not detected Then you need to do what they call a block test.A block test kit you can buy at a aftermarket auto parts store.A block test is where you have the cap off of the radiator and put a tube in it to measure to see if any exhaust fumes are coming through your coolant passages. (blown head gasket ETC)
My 2000 Cadillac Deville northstar motor is overheating and loosing coolant. I've changed thermostat twice?
Radiator caps are a couple of bucks. You can try that. Rare, but caps lose their sealing ability.



If you added windshield washer fluid to the cooling system, that causes suds and overflow.



More than likely a blocked radiator core. Ask a radiator shop the charge if you pull the radiator or the charge if they pull it for a pressure check.



If you smell antifreeze in the passenger compartment through the defrost, that points to head gasket. Have the cylinders compression checked. Blown head also pumps oil out your exhaust. Your tailpipe will be black instead of gray.



On a different car, the last option is what I paid for after the mechanic misdiagnosed the first three repairs and charged me anyway.
Changing the thermostat doesn't really do much, they rarely go bad. If you still think it is the thermostat, remove the thing, you can run an engine without one. But I don't think it's your problem. Did you have a lot of miles on the vehicle? It could be a head gasket as someone else mentioned. It could also be they the radiator. After a lot of miles they don't work as efficiently as when new. You have all the same conditions that I had in my Mustang years back. I replaced the head gasket, radiator cap, and took out the thermostat and it still overheated. They problem turned out to be the radiator. gl
water pump radiator or blown head gasket id look for white lines on the radiator that would show leaks as the steam dries it stains the radiator or hoses or near the water pump if it blows white steam from exhaust you have bad head gasket
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  • 1997 Ford F150 4.6 liter only getting heat occasionally, changed thermostat already problem still exists?

    I have a 1997 Ford F-150 4.6 Liter 84,000 miles. The truck takes forever to heat up, when it does I get hot heat, but then the temp gauge starts to drop and the heat goes cold. Sometimes the gauge doesn't drop and the heat goes cold. The gauge never goes beyond about a quarter of the way up. The blower works. I changed the thermostat, what I thought was the most obvious for what seems to be over cooling, but the problem still exists. I checked all lines and fluid is flowing through the heater core as well. At a complete loss??????
    1997 Ford F150 4.6 liter only getting heat occasionally, changed thermostat already problem still exists?
    Check and fill the Coolant again and into the radiator, because there is a giant air bubble that moves around after you drain and then refill the coolant once. Sometimes on my truck the coolant dows not flow from the plastic overflow reservoir into the radiator, that's why I said to fill the radiator directly again.



    I think the factory thermostat rating is about 195 degrees or so, so check the package.
    1997 Ford F150 4.6 liter only getting heat occasionally, changed thermostat already problem still exists?
    Is the heater core plugged? Or the lines to it?

    Ford escort van heater wont work. Have changed thermostat. Blower etc ok?

    Hi can anyone help? I've noticed as the weather is getting colder the heater in my wee van is blowing cold air. I've checked the water level, fitted a new thermostat, with no effect. I can get a slight heat if I set the temp at max and the blower at min, but nothing to speak of. The van temperature gauge does not overheat. no sign of any emulsification in the radiator water. I've tried squeezing the heater hose in case there is an air lock. Still wont work.

    Please someone help before I freeze to death.



    Frank Mc
    Ford escort van heater wont work. Have changed thermostat. Blower etc ok?
    Is the linkage to the heater Matrix connected ?

    Is the Matrix air locked ? bleed

    are the shutters letting air into car open ?

    squeezing pipes will not work.
    Ford escort van heater wont work. Have changed thermostat. Blower etc ok?
    I assume the heater hoses are cool rather than hot.



    My old Escort van had a little air vent in the heater hose to allow you to get rid of air locks. If yours doesn't have one, disconnect both hoses %26amp; flush through the heater matrix with a hosepipe. Refill the cooling system by parking the van on as steep an uphill slope as you can (or use ramps). This should keep the heater hoses full.
    I've done a little research to determine the components used in this particular heater system. Being that I am from America and we don't have Escort Vans, I will have to rely on service maunual to determine how the heater system operates. The previous answers are very good suggestions. In my experience most of the time this condition is caused by lack of coolant flow to the heater core. This can be caused by a couple of different reason. First, an airlock in the system, which can usually easily be corrected by bleeding the coolant system. This bleeder screw will normall be located on top of the engine somewhere around the thermostat housing/upper radiatior hose. In short, ensure that the cooling system is actually full. Start the vehichle, remove the raditor cap, turn on the heater to full speed and temperature, and allow to reach operating temperature, After preparing the system to fill, begin filling at the radiator. Once the engine has reached operating temperature, the thermostat should open and any air pockets should be forced back out of the system. After ensuring the system is full, replace the radiator cap, and check the heater output temperature. If it is still not producing the desired output temperature. Place you hand on the Intake and Output hose of the heater core. If the system is working properly both should be fairly hot. Almost too hot to keep your hand on the hose very long. If both hoses are not hot, you have one of two problems. Either the heater core has an air pocket causing an air lock or from the research I have done, the heater control valve is not allowing the proper flow through the heater core. I believe this is a project that you will need to check these items and get back with me with what you found. I will be more than happy to walk you through the repair process to get your heater working. I don't think this is a serious or expensive repair, but you do need the knowledge to know what to check and how to correct the problem when we find it.

    Good luck and Hope to hear from you soon,
    it's the the valve that switches between cold and hot air as you turn the temp dial, i can't remember what the exact name of it is. The screw that it piviots on will have seized, it's a common fault on lots of Fords.
    they call it blend door, yours might be cable operated ,check the cable when you move the temperature knob,feel if there is resistance,,some times the lock that hold the cable just come off making the blend door not to move fully
    I had a build up of corrosion in one of my water pipes where it connected to the aluminum head. If your heat wasn't used for 6 months during the summer, a blockage could form due to the coolant not circulating through the hoses, pipes, and heater core.
    I'm not familiar with the ford escort van. However you might want to check the lines coming out of your heater core in the engine compartment. After having the vehicle get up to operating temp and the heater on you should be able to feel both lines coming out of the heater core. Both of these lines should be hot! If one of the lines are still on the cool side you might have a blockage in your heater core. You can try clearing the blockage or replacing the heater core.