Bosch GWH 635 ES Service Bulletin Booklet

Bosch GWH 635 ES

20 pages

To Next Page

To Next Page

Page #1 background image

Loading...

Page #1 background image

Service Bulletin Booklet

For Bosch model water heaters

GWH 635 ES, GWH 635 ESO,

GWH 2400 E, GWH 2400 EO,

AQ250SX, AQ250SXO

Table of Contents

Other manuals for Bosch GWH 635 ES

User Manual36 pages

Questions and Answers:

J
Joseph AdamsJul 30, 2025
Why won't the burners ignite on my Bosch Water Heater when I turn on the hot water?
- K
  kaufmanhectorJul 30, 2025
  If the burners on your Bosch Water Heater don't ignite when you turn on the hot water, it could be due to several reasons. First, ensure the cold water inlet is connected to the correct side of the heater. Second, the water flow rate might be too low; a minimum of 0.8 gallon/minute (3 l/m) is needed to activate the heater. Third, a dirty cold water inlet filter screen can cause this issue; remove and clean it, also check the faucet aerator screens. Finally, a crossover in the plumbing could be the problem. To check this, shut off the cold water supply to the heater and individually open each hot water tap; there should be no water flowing under constant pressure.
D
Duane NunezAug 4, 2025
How to adjust the temperature if the water is too hot in my Bosch Water Heater?
- V
  Valerie GonzalesAug 4, 2025
  If the water from your Bosch Water Heater is too hot, the temperature selection might be set too high. You should lower the temperature adjustment either on the heater itself or via the wireless remote, if applicable.
B
brandon55Aug 10, 2025
What to do if Bosch GWH 635 ES Water Heater water is not hot enough?
- M
  Mckenzie SmithAug 10, 2025
  If the water from your Bosch Water Heater isn't hot enough, the temperature selection may be set too low; increase the temperature adjustment on the heater. Also, the BTU input could be too low due to inadequate gas line sizing. Check specifications in chapter 2.10 - 2.12. The GWH-635-ES requires adequate gas pressure to reach desired temperatures. To compensate for inadequate gas supply or lack of gas pressure, the GWH-635-ES will effectively reach the selected output temperature by reducing the hot water flow rate.
A
Ashley JohnsonAug 14, 2025
Why is the water flow/pressure low in my Bosch GWH 635 ES?
- J
  Joseph WilliamsAug 15, 2025
  Low water flow or pressure in your Bosch Water Heater can occur for several reasons. It might be because too many hot water applications are being used at once, exceeding the heater's capacity. The GWH-635-ES model effectively supports two 2.0-2.5 gpm shower heads simultaneously or multiple sink applications, but greater demands will reduce flow. Inadequate gas line sizing leading to low BTU input could also be the cause, so refer to specifications in chapter 2.10 - 2.12. Another potential issue is a dirty cold water inlet filter screen, which requires removal and cleaning, and also check faucet aerator screens.
W
Wayne EdwardsAug 19, 2025
Why does the hot water temperature fluctuate in my Bosch GWH 635 ES?
- D
  Donna GriffinAug 19, 2025
  If the hot water temperature fluctuates or the unit deactivates in your Bosch Water Heater, it could be due to unbalanced pressure in the water lines; a pressure balance valve may help. Alternatively, if the outlet water temperature is set too high, the heater can produce temperatures that are excessively hot.
I
Isaiah FrancoAug 25, 2025
Why is my Bosch GWH 635 ES Water Heater burner noisy during operation?
- S
  smithnicoleAug 25, 2025
  If your Bosch Water Heater's burner or heater is noisy during operation, the CO2 range might be out of adjustment. Ensure the cover is in place to confirm CO2 readings, as operating the heater with the cover removed may cause a noisy or unstable burner.

Bosch GWH 635 ES Specifications

General

Type	Tankless
Fuel Type	Natural Gas
Energy Factor	0.82
Ignition Type	Electronic
Maximum Temperature	140°F
Gas Connection	1/2 inch
Water Connection	1/2 inch

Related product manuals

Preview: Bosch GWH-635-ES-N

Bosch GWH-635-ES-N

Bosch GWH 715 ES

Preview: Bosch GWH 2400 ES

Bosch GWH 2400 ES

Bosch GWH C 800 ES

Preview: Bosch GWH 2700 ES LP

Bosch GWH 2700 ES LP

Bosch GWH 2400 ES NG

Preview: Bosch AquaStar GWH 2700 ES NG

Bosch AquaStar GWH 2700 ES NG

Bosch GWH 16-2 G Series

Preview: Bosch GWH 10-2 G Series

Bosch GWH 10-2 G Series

Preview: Bosch Aquastar GWH 1600 H N

Bosch Aquastar GWH 1600 H N