Do you have a troubleshooting service manual service manual

Copy following link for FV lockout:
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html

GE water heater made by Rheem has a glass vial called TRD.
http://waterheatertimer.org/How-to-repair-Rheem-TRD.html

Copy following link to troubleshoot and see service manual by type of gas control valve:
Rheem does not post service manuals
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Copy following link for troubleshoot by type of gas control valve.
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

Also: Scroll up on same page for Pressure Switch heading.

Lochivar is made by Bradford White I believe.
Same troubleshoot page has link to Bradford White service manuals, and service manuals posted by AO Smith, in case this product is through one of their subsidiaries.
Rheem does not make this product, good thing for you because Rheem doesn't post service manuals.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Instructions for lighting Reliance 660 are located on the side of water heater just above the gas control valve.
If you are having other problems, read your product manual, or go to reliance for copy of manual, and read troubleshoot section:
http://www.reliancewaterheaters.com/lit/om.html

Unfortunately Rheem-Reliance does not post service manuals for their product. However other companies do post service manuals that might be similar to your water heater

Copy following link for troubleshoot service manual by type of gas control valve:
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Before calling service technician, open following links for Rheem/Paloma troubleshoot resources including error codes:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html
http://waterheatertimer.org/pdf/No-Error-Code.pdf

C2 11 is no ignition.
Clean combustion parts yearly as recommended in manual is first step.
Other causes can be loose wiring, bas gas valve, dirty air intake, bad venting, bad sensors etc.
Test these parts using service manual. Call Rheem since Rheem does not post service manuals.

Before calling service technician, open following links for troubleshooting resources including Rheem phone, chat, error codes, general maintenance pdf, and generic service manual:
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html
http://waterheatertimer.org/pdf/Tankless-maintenance.pdf
http://waterheatertimer.org/pdf/Tankless-service-manual.pdf

Error codes are considered start point for troubleshooting.
Error 11 is 'no ignition' or 'no gas'
You have checked gas and pressure, and had parts cleaned.
Other causes can include: igniter wiring, bad igniter, loose wire on gas solenoid, bad solenoid, improper grounding.

Do you want service manual? Parts list manual? Or installation manual?

Service manual:
http://www.bradfordwhite.com/images/shared/pdfs/manuals/44943A.pdf

Other BW manuals with parts, installation, and service:
http://www.bradfordwhite.com/documentation/residential/gas.asp

Other resources:
http://waterheatertimer.org/How-to-install-gas-water-heater.html#troubleshoot

Before calling service technician, open following link for Bosch troubleshooting resources including online support, possible manual, and service bulletins.
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

Read manual for troubleshooting, advisories and required maintenance.

Upvote the help.
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

Before calling service technician, open following link for troubleshooting resources.
Manual is best place to start, open manual and word search 'troubleshoot'
Bosh also has troubleshoot page for most/some models
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

Suggest that you read manual for required maintenance.
Service technician can also give tips and information for keeping your unit working.

1) Dirty water implies degraded metal inside unit:
The anode rod protects metal parts. Once anode is depleted, metal parts react with water.

2) Open following troubleshoot pdf showing Ariston parts
http://waterheatertimer.org/pdf/How-to-Troubleshoot-Bosch-Ariston-Water-Heater.pdf

3) Ariston manual: Read manual cover to cover, make sure water heater receives yearly maintenance as outline in manual.
http://waterheatertimer.org/pdf/Bosch-GL_English.pdf

4) Information on anode rods
http://waterheatertimer.org/Replace-anode-rod.html

5) For Bosch gas and electric tankless: Open following link for troubleshooting resources, including Bosch contact information, typical manuals, error codes, tech support, parts, fuel-saver calculator, service bulletins, water heater forum, fixya links, disclaimers, and links for finding service technician.
http://waterheatertimer.org/Troubleshoot-Bosch-Tankless-water-heater.html

6) Add a comment with your experience so others with same-similar problem can benefit.

Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

If this is tank-type water heater, open following link for troubleshoot pdf and other helpful information before calling service person:
http://waterheatertimer.org/How-to-install-gas-water-heater.html#troubleshoot

Open following link for Rheem/Paloma/Richmond/Ruud tankless troubleshoot resources including error codes, self help, manuals, parts links, tips, and contact information.
http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.html

Read manual cover to cover, make sure water heater receives yearly maintenance as outline in manual.

Add a comment with your experience so others with same-similar problem can benefit.

Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.