Water heater control system

• US 4,166,944 A
• Filed: 07/25/1977
• Issued: 09/04/1979
• Est. Priority Date: 07/25/1977
• Status: Expired due to Term

• Current Assignee: Scott Kenneth W As Trustee
• Original Assignee: Kenneth W. Scott
• Inventors: Scott, Kenneth W.
• Primary Examiner(s): Bartis, A.
• Application Number:
  US05/818,967
• Time in Patent Office: 771 Days
• Field of Search: 126/351, 126/374, 126/361, 126/362, 236/47, 236/20, 219/327-331, 219/334, 219/337, 219/508, 219/310, 219/312, 219/515, 137/341
• US Class Current: 392/463
• CPC Class Codes: F24D 17/0078 Recirculation systems

Abstract

A water heater control system is provided to lower the temperature to which hot water is heated during periods of low use, and raise the temperature back up during periods of peak demand. The unit described herein is adapted for use on a recirculating hot water system used in apartment buildings and includes a first thermoswitch disposed on the outflow pipe from the hot water tank which feeds this recirculating system. This pipe is hotter during periods of low use because the heater is adequate to provide continuous supply of very hot water which has not been drained by tenant use. Thus this thermoswitch is directly wired to a thermostat control to reduce the heater temperature when the thermoswitch is hot. A second switch is mounted on the cold water inflow supply pipe into the water heater, this thermoswitch being wired in series with the first thermoswitch, this switch being closed only when it is cooled, similar to the first thermoswitch, so that when the inflow supply pipe is cool due to high usage and thus continuous input of cold water, the second thermoswitch closes, which permits the first thermoswitch to control the system. During quiescent periods of low use, the inflow warms due to conduction from the hot water tank, thus opening the second thermoswitch and making the first switch ineffective.

Claims

1. A water heater control system comprising:

(a) a water heater with a heating means and having a hot water outflow line and a cold water inflow line;

(b) an adjustable water temperature control device operatively connected to said water heater for controlling operation of said heating means;

(c) first temperature sensing means disposed in operable proximity to said outflow line and responsive to the temperature of said outflow line;

(d) a second temperature sensing meand disposed in operable proximity to said inflow line and responsive to the temperature of said inflow line;

(e) electrically operated water temperature control device setting means electrically coupled in circuit with both of said temperature sensing means and mechanically coupled to said water temperature control device, said setting means being,

(i) operable for setting said control device in an elevated temperature mode in response to the temperature in said outflow line reaching a predetermined low and the temperature in said inflow line dropping below a predetermined low; and

(ii) operable for setting said control device in a reduced temperature mode in response to the temperature in said inflow line exceeding said predetermined low and the temperature in said outflow line exceeding a separately predetermined level above said predetermined low.

2. Structure according to claim 1 wherein said water temperature control device is a thermostat.

3. Structure according to claim 1 wherein said water temperature control device is an energy gate for controlling energization of the heating means of said water heater.

4. Structure according to claim 1 wherein said first and second temperature sensing means are both thermo-switches coupled in series to said control valve setting means.