{"product_id":"rolachem-h-block-roller","title":"Astralpool \/ Rolachem H Block Roller - RC8, RC9, RO9, RP9 Dosing Pumps - 521015","description":"\u003ch3\u003eAstralpool \/ Rolachem H Block Roller - RC8, RC9, RO9, RP9 Dosing Pumps - 521015\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003eWe keep these physically in stock for fast shipping or local pick-up, unlike most drop-shipping websites.\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003e\u003cstrong\u003eShipped from VIC, NSW, WA, QLD\u003c\/strong\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eGenuine Astralpool H block, part 521015, the roller carrier inside the pump head of a Rolachem peristaltic dosing pump. Astralpool lists it simply as H BLOCK in its Rolachem spare parts pages.\u003c\/p\u003e\n\u003cp\u003eThe H block is the rotating part that carries the rollers around the inside of the pump head. As it turns, the rollers squeeze the tube against the housing and push chemical along it. Nothing else in the pump touches the chemical, which is why the roller block and the squeeze tube do all the wearing.\u003c\/p\u003e\n\u003ch3\u003eWhen the H Block Is the Problem\u003c\/h3\u003e\n\u003cp\u003eAstralpool's own Rolachem troubleshooting lists a broken roller or H block as a cause of a pump that is not dosing properly, alongside a cracked pump head, an empty chemical drum and a squeeze tube that has come off the barb.\u003c\/p\u003e\n\u003cp\u003eSigns the H block has failed:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe motor runs but no chemical moves along the tube.\u003c\/li\u003e\n\u003cli\u003eA roller is missing, seized, or no longer turns freely on its pin.\u003c\/li\u003e\n\u003cli\u003eThe block is cracked, or an arm has snapped.\u003c\/li\u003e\n\u003cli\u003eDosing has become erratic or the output has dropped well below the set rate.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf the motor does not turn at all, the fault is the gearbox and motor or the board, not the H block.\u003c\/p\u003e\n\u003ch3\u003eReplace the Squeeze Tube at the Same Time\u003c\/h3\u003e\n\u003cp\u003eA squeeze tube and a roller block wear together, and a worn tube is the far more common failure of the two. If the H block has broken up, inspect the tube before refitting, because debris and a damaged tube will take out the new block as well. The chlorine and acid tubes are different parts, so order the one that matches the pump you are working on.\u003c\/p\u003e\n\u003cp\u003eAcid and chlorine should never share a tube or a pump head.\u003c\/p\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePart number: 521015\u003c\/li\u003e\n\u003cli\u003eAstralpool description: H BLOCK\u003c\/li\u003e\n\u003cli\u003eFunction: roller carrier inside the peristaltic pump head\u003c\/li\u003e\n\u003cli\u003eListed for: Rolachem RC8, RC9, RO9 and RP9 dosing pumps\u003c\/li\u003e\n\u003cli\u003eQuantity required: 1 per pump head on RC9, RO9 and RP9, 2 on the RC8\u003c\/li\u003e\n\u003cli\u003eBrand: Astralpool (Fluidra)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eRelated Rolachem Dosing Parts\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/chlorine-squeeze-tube\"\u003eChlorine Squeeze Tube, Rolachem - 520113\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/acid-squeeze-tube\"\u003eAcid Squeeze Tube, Rolachem - 520112\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/astralpool-viron-equilibrium-rolachem-rc1-rc9-ro9-rp9-eq-series-pump-head-face-plates-pair\"\u003ePump Head Face Plates, Pair - 521010\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/astralpool-rolachem-squeeze-tube-clamp\"\u003eSqueeze Tube Hose Clamp - 520115\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/chlorine-acid-check-valve-one-way-valve-6mm-rolachem-chemigem-astralpool-siesta-etc\"\u003eChlorine \/ Acid Check Valve, 6mm - 520118\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/chlorine-acid-supply-tube-6mm-rolachem-chemigem-siesta-astralpool-etc\"\u003eChlorine \u0026amp; Acid Supply Tube, 5 to 6mm, per metre\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/astralpool-acid-chlorine-venting-kit\"\u003eAcid \/ Chlorine Drum Venting Kit - 78366\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/astralpool-mixing-cell-complete\"\u003eMixing Cell Complete, Body with Unions - 520139\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/ph-probe-astralpool-eq\"\u003epH Probe, eQuilibrium \/ Rolachem - 525147\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/astralpool-rolachem-ph-calibration-solution-7-5-100ml-200ml\"\u003epH 7.5 Calibration Solution\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/astralpool-rolachem-orp-calibration-solution-100ml-redox-700mv-600117\"\u003eORP Calibration Solution 700mV - 600117\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat does the H block do?\u003c\/strong\u003e\u003cbr\u003eIt is the rotating roller carrier inside the pump head. The rollers it carries squeeze the tube against the housing to move chemical along it, which is how a peristaltic pump works.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMy Rolachem motor runs but nothing is being dosed. Is it the H block?\u003c\/strong\u003e\u003cbr\u003eIt can be. Astralpool lists a broken roller or H block as a cause, along with a cracked pump head, a squeeze tube that has come off the barb, and an empty chemical drum. Check the tube first, since it is the more common failure.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow many do I need?\u003c\/strong\u003e\u003cbr\u003eAstralpool's spare parts lists show one per pump head for the RC9, RO9 and RP9, and two for the RC8.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShould I replace the squeeze tube as well?\u003c\/strong\u003e\u003cbr\u003eUsually yes. The tube and roller block wear together, and fitting a new block against a worn or damaged tube will shorten its life.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it suit a Viron eQuilibrium?\u003c\/strong\u003e\u003cbr\u003eThe matching pump head face plates, 521010, are listed for Viron eQuilibrium and EQ-Series as well as Rolachem. Astralpool's own catalogue lists the 521015 H block under Rolachem only, so send us a photo of your pump head and we will confirm before you order.\u003c\/p\u003e\n\u003chr\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan style=\"text-decoration: underline;\"\u003eManufacturer Catalogues, Diagrams \u0026amp; Part Numbers:\u003c\/span\u003e\u003c\/strong\u003e Need exploded views, spare part numbers, product numbers, diagrams, or more product information? See the manufacturer catalogues below.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003e \u003ca href=\"https:\/\/hasp.com.au\/pages\/Astralpool_Catalogue_2026\"\u003eAstralpool Catalogue 2026\u003c\/a\u003e | \u003ca href=\"https:\/\/hasp.com.au\/pages\/Zodiac_Catalogue_2026\"\u003eZodiac Catalogue 2026\u003c\/a\u003e \u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan style=\"text-decoration: underline;\"\u003eImportant Before Ordering:\u003c\/span\u003e\u003c\/strong\u003e Please ensure you order correctly. Confirm this product is suitable before ordering. Use the catalogues above, seek professional assistance, or \u003ca href=\"mailto:shop@hasp.com.au\"\u003econtact us\u003c\/a\u003e with photos of your existing part, model details, serial numbers, and any labels.\u003c\/p\u003e\n\u003cp\u003eAs with all products, these must be diagnosed and fitted by a qualified and experienced person.\u003c\/p\u003e\n\u003chr\u003e\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does the H block do?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"It is the rotating roller carrier inside the pump head. The rollers it carries squeeze the tube against the housing to move chemical along it, which is how a peristaltic pump works.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"My Rolachem motor runs but nothing is being dosed. Is it the H block?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"It can be. Astralpool lists a broken roller or H block as a cause, along with a cracked pump head, a squeeze tube that has come off the barb, and an empty chemical drum. Check the tube first, since it is the more common failure.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How many do I need?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Astralpool's spare parts lists show one per pump head for the RC9, RO9 and RP9, and two for the RC8.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Should I replace the squeeze tube as well?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Usually yes. The tube and roller block wear together, and fitting a new block against a worn or damaged tube will shorten its life.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Does it suit a Viron eQuilibrium?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The matching pump head face plates, 521010, are listed for Viron eQuilibrium and EQ-Series as well as Rolachem. Astralpool's own catalogue lists the 521015 H block under Rolachem only, so send us a photo of your pump head and we will confirm before you order.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"ASTRALPOOL","offers":[{"title":"Default Title","offer_id":67763927253181,"sku":"521015","price":83.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0372\/5253\/files\/astralpool-rolachem-h-block-roller-rc8-rc9-ro9-rp9-dosing-pumps-521015-587.webp?v=1791949571","url":"https:\/\/hasp.com.au\/products\/rolachem-h-block-roller","provider":"Heater and Spa Parts","version":"1.0","type":"link"}