I don't think it's a clicking sound, yours sounds more like jawbone as they sometimes click when swallowing. I have heard more of a thub,thub sound couple of times I had it when very stressed out taking care of my parents few yrs back, Haven't had it since they passed away. Usually have low BP . Is your BP high, I don't think it could be heart at all, just where the jaw hinges on both sides back by your ear, for awhile when they were trying to realign my jaw to get rid of migraine headaches drs were doing a surgery on the jawbones of people but about 10 yrs later it came out that they were mostly a mistake as the problems got worse.(but they made lots of money on the surgeries) Might be like some people can crack their knuckles & others can't just a family trait!

May want to read this for safety: http://www.mclaughlin-air.com/lennoxpressrelease1.htm When is the last time you had the furnace inspected? The Lennox Pulse furnaces were some pretty efficient furnaces from what I've read. For replacement there are some nice modulating furnaces out there from Rheem and York. Other than that there is always the Carrier Infinity.

I boiled some eggs this morning and at the end of the designated boiling time (at a setting of 5.5), I turned down the hob into the lower settings. I had to choose a setting that was high enough to cause bubble formation because at the lowest settings the induced heat just conducted away. Settings between 3 and 4 would cause effects that could be easily observed. It was evident that the power to the hob was modulating at a roughly 1-Hz rate. Hence my experience is not the same as Gary's and it is possible that my E'lux clone has a different circuit than his. There are no noises associated with this modulation, and it occurs (for the particular pot and water level) at an energy input too low for bubbles to even detach from the pot bottom and potentially make noise at the surface. I don't consider this a defect; but rather a design choice that likely results from some trade-off that wouldn't be apparent to someone who doesn't design induction cooktops for a living. Perhaps switching at a higher frequency would induce additional circuit heating. In any case, induction ready pots and pans have thicker bases with longer thermal time constants, so this effect may not be apparent with their use. Sometime I'll try a handy Emeril pan and see what happens. kas

Joe -- the pulsing you are seeing is pretty much endemic to lower-priced portable induction cookers (PICs). The other name for what Kaseki called "duty cycle" is "pulse width modulation" (PWM). Microwave ovens use the same technique, switching power on and off at higher or lower frequency to simulate higher and lower power settings. The idea is that the heat averages out , although the average between the state of boiling and still water may not be the same as water at a more steady heat level. Having more power settings and/or settings targeted to temperature doesn't necessarily address the PWM frequency unless there is some kind of in-pan temperature probe. Induction units with in-pan probes are becoming available but still seem to be very expensive. PICs can be built with high-frequency switching where the on-off switching happens so many times per second --- as Weed describes --- that the pulsing is rarely perceptible even with thin pans. Trouble is, the high frequency switching components are comparatively expensive. Using heavier pans (like the LeCrueset you mentioned) will help somewhat on better quality PICs and hobs but, as you are seeing, does not solve the pulsing problem when using the less expensive PICs like the one you apparently have. If you were in the US, I would point you to the Century Life blogs site (link to their article on PICs). I don't know anything about the T-Fal you asked about but suspect that it is made either by Fagor or one of the Chinese factories to which many PIC brands sub-contract their production. Most, if not all of those, have the crude PWM electronics. The Century Life site recommends the Vollrath Mirage PICs for units that do not exhibit the boil-still-boil-still pattern. These are commercial units and, over here, the Vollrath units have been priced at about half-way between the lower-end PICS and what is usually charged here for the commercial-grade Cookteks that Kaseki and Weed have. Don't know if that will hold true in the UK but I believe that the Mirage units are available in the UK., at least from food service companies. You might try following up on that and seeing if searching on "Vollrath Mirage Induction" turns up some similar units from other brands which might be more favorably priced.