{"id":10048,"date":"2026-08-21T18:13:35","date_gmt":"2026-08-21T22:13:35","guid":{"rendered":"https:\/\/cetechsupport.com\/?p=10048"},"modified":"2026-08-21T18:13:35","modified_gmt":"2026-08-21T22:13:35","slug":"code-53-42-ost-shorted-backup-heat-only","status":"publish","type":"post","link":"https:\/\/cetechsupport.com\/es\/code-53-42-ost-shorted-backup-heat-only\/","title":{"rendered":"Code 53-42 OST Shorted &#8211; Backup Heat Only"},"content":{"rendered":"<div class=\"wp-block-group fault-code-summary is-layout-flow wp-block-group-is-layout-flow\"><div class=\"wp-block-group__inner-container\">\n\n<h2 class=\"wp-block-heading\">Fault codes covered<\/h2>\n\n\n<p class=\"wp-block-paragraph\"><strong>53-42<\/strong><\/p>\n\n<\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The suction thermistor is required for control of the outdoor EXV in HP systems. Similar to \u201cOST Open\u201d fault, heating mode operation will be locked out if the OST is determined to be open or shorted. Cooling operation will be allowed if OST is not functional, though on HP systems the malfunction will be displayed on wall control screen (26VNA\/27VNA). This will remind homeowner to repair the sensor before heating season. Shorted OST sensor value will default to \u201c47\u201d on status or checkout display. The sensor is monitored continuously and if resistance is below 1kohm for 1 second this fault will occur. Once sensor value rises above 1kohm for 1 second the fault will clear.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Measure resistance value of thermistor at the PCM connector. If value is below 1kohm, look for bare wire, short in the wiring, or at the connector itself. If no bare wires or shorts are observed, replace sensor. If measured resistance is within allowable range, replace PCM.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<p class=\"has-small-font-size wp-block-paragraph\"><em>Source: ACHPVSR454-02SM troubleshooting pages.<\/em><\/p>","protected":false},"excerpt":{"rendered":"<p>Troubleshooting guidance for fault code(s) 53-42.<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_uag_custom_page_level_css":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[88],"tags":[149],"class_list":["post-10048","post","type-post","status-publish","format-standard","hentry","category-fault-code-troubleshooting","tag-fault-code-53-42"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"trp-custom-language-flag":false},"uagb_author_info":{"display_name":"Carrier Enterprise","author_link":"https:\/\/cetechsupport.com\/es\/author\/joshg\/"},"uagb_comment_info":0,"uagb_excerpt":"Troubleshooting guidance for fault code(s) 53-42.","_links":{"self":[{"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/posts\/10048","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/comments?post=10048"}],"version-history":[{"count":1,"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/posts\/10048\/revisions"}],"predecessor-version":[{"id":930408,"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/posts\/10048\/revisions\/930408"}],"wp:attachment":[{"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/media?parent=10048"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/categories?post=10048"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cetechsupport.com\/es\/wp-json\/wp\/v2\/tags?post=10048"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}