今天我们要讲的是如何省掉５００块钱的事情。钱不多，但学本事。
The story goes like this, a 13 years old house, no heating. You can hear the heating unit trying to do something, but no fan was on to blow out air, hot or cold.
1 If place fan to ON, the blower works fine, then it narrows down to mainly to heating unit.
2 Open the furnace, with care and observe exactly what is going on.
3 The purticular unit goes like such: 1, a small fan is turned on; 2, a little click and 3 a little hissing; 4, no light, no fire; 5, unit stops after 5 minutes.
4 Search Google and find the following reasons, in the likelihood
- No power ---> not true
- No gas ---> not true
- Bad igintor --> ?
- Bad pressure switch --> ?
- Bad circuit board --> ?
5 look closer to the ignitor and see this one <img src=http://www.hvacpartsoutlet.com/images/badhsi.jpg>. It went to this after taking out <img src=http://toad.net/~jsmeenen/images/ignitor.jpg>. A good one looks like this <img src=http://www.diychatroom.com/attachments/f17/26190d1288235623-carrier-58pav070-12-error-code-31-hot-surface-ignitor.jpg>
6 search internet and find the cheapest one
7 replace with care following Youtube video
8 ... guess
