Ed Pawlowski於 2019年2月6日星期三 UTC-8下午2時33分49秒寫道：
On 2/6/2019 5:02 PM, KMT wrote:
The 13 year old hydronic heating system in my house seemed to work fine until this winter. It used to warm up the house in 2~3 hours (say from 66 f to 70 f on not so cold days ). But I have noticed the temperature is not coming up fast enough this winter. The thermostat in the room is set at 61 f overnight and starts to call for heat at 7 AM for 68 f. So for the past few days at 7 AM, the thermostat reads 59 f and starts calling for heat. The boiler cycles on and off through out the day and at 12 PM, The thermostat reads around 60 f to 61 f. ONLY 1~2 degrees up for running 5 hours!!!! The system uses Honeywell Aquastat L4103D and L6006A. The dial points at 190 f on L4103D and its set at 140 f on L6006A with Diff 5 degrees. Is this the right setting? According to the gauge on the boiler, it is tuned on at 130 f and off at 190 f. It runs about minutes before shutting off and the next cycle comes on in about minutes. Is this right? Why is the house not warming up like it used to be?

First, what is the outdoor temperature? If you are used to dealing with
20 to 30 degrees and now it is suddenly -20, the warm up time will be
considerably longer and perhaps never achieved.

If it takes up to 2 hours to get from 66 to 70, the sizing is marginal
at best. My house can go from 62 to 70 in less than an hour.

There are three considerations. One is the size of the boiler itself.
If it is cycling, it is probably adequate. The next thing is the amount
of heating surface, radiators, baseboard, whatever. If you don't have
enough, it cannot move the heat from the boiler into the room.

The next is flow. Is the circulating pump working properly? Is the
water moving the way it should be? Feel the pipe and be sure it is hot
all the way through the loop. There will be some drop along the way as
it gives off heat, but should not be dramatic. The circulator is the
first thing I would check. They do go bad.

It's between 17 f and 27 f in the daytime and 5 f overnight. I am a newbie here. I don't know if I got this right but I think the size of the boiler and the heating surface should be fine because I remembered standing on hot tiles in the kitchen when the thermostat was calling for heat,last winter and the house was warm.. As for the circulating pump, it was hot when I felt it so I think its working properly? The pipes are like "ouchy" hot when I felt them but when I was standing on the kitchen tiles, the surface only felt lukewarm. It used to be very warm before.