In Bell Canada territory, a service charge of $ 95 will apply if Bell comes to your home and finds the trouble to be within your home wiring or telephones.

So it would be wise to do the following before calling:

1- With the prevalence of a lot of cheap, imported telephones on the market, many more problems are caused by these cheap instruments.  An internal short within the instrument itself can cause the telephone company computer to temporarily shut the line down until the short disappears. One by one, disconnect your phones, and check from one of the others to see if dial tone has returned. If so, the telephone you last disconnected is at fault. Dont try to fix it, throw it out, and if it is a cheap telephone, purchase a decent quality replacement.

2- If you have a professionally installed alarm system, disconnect the plug from the special line seizure jack provided to you by the alarm installing company (this is usually located adjacent to the alarm panel, and has a thick grey cord running from the jack itself  to the inside of your alarm panel). If this returns dial tone, then the alarm panel is trying to call the station for some reason, and cannot, and is incorrectly holding up the line. Call your alarm company for service.

3- If you are "handy", and own a voltmeter, set it to read DC voltage, virtually any range from 15 to 200 Volts (this is low voltage with no real amount of amperage  so you can't get electrocuted by the telephone lines as you can from the AC power lines in the home). Then disconnect the "Tip" and "Ring" leads (green and red usually) to isolate the total telephone system within the house, from the outside line. Put your voltmeter leads across the terminals of the telephone line where the telephone network terminates in the basement of your home (called the demarcation block) and where you have disconnected the house phones from the incoming lines, and you should see voltage. If it shows reverse voltage, don't worry, you are only looking for the presence of voltage. If the voltage is very low - in the order of 3 volts -   there is probably water in the outside cabling leading back to the telephone company - this requires telephone company attention. If the voltage is "healthy" - 15 to 100 -  the problem is somewhere within your home wiring or telephones ! If there is no voltage across the telephone lines coming into the home, the problem definately is the responsibility of the telephone company ! 

4- An even simply way than the above to isolate the problem, is to plug an existing, working telephone into the line seizure jack just above the alarm panel. If there is no dial tone on that phone, the problem is definately within the home telephone network (more likely), or within the alarm system (far less likely). If there is dial tone, you can be reasonably sure that the Bell line coming into the house is working properly (however, do make an outgoing call from this phone to ensure the line is truly working....). By plugging in at this point in the phone network, you are accessing the dial tone from Bell in front of both the alarm system and the home telephone wiring.

Remember, the telephone line trouble indicated by your alarm system is normal when there is no dial tone present. In most cases, the alarm is not the cause of the trouble, but is simply responding to the trouble as it is designed to do.

Once you have isolated the problem to be within the telephone company's wiring outside the home, you may safely call Bell with no worry of being assessed a bill for their services !!

NOTE: On  occasion, you can have problems with the alarm panel trying to answer the line when it receives a certain type of double ring from Bell. This will usually be indicated by the calling party hearing what sounds like a fax trying to answer the phone when they are dialing in, and complaining to you about this. This problem can be alleviated by having your alarm dealer dial in to your panel and turning off the "answering machine override" feature (this is a feature that allows your dealer to access your panel when it has to fight with an answering machine trying to answer the incoming call at the same time). In rare cases, the dealer may be required to set the panel not to answer an incoming call at all, in which case, he will require your future help at the keypad to force the panel to answer his call when needed.

If you are currently one of my alarm system customers, PLEASE call me before you call the telephone company. I will at no charge to you, come out and check your telephone system to ensure that Bell's visit will not cost you needlessly..!!

There is never a charge for my service to do this