--- title: "Rational Service 42.1: the water supply to the steam generator is not right" description: "What Service 42.1 means on Rational Service 42.1: the water supply to the steam generator is not rights, what to check before booking, and when it is not a…" url: "https://commercialappliancerepair.center/error-codes/rational-service-42-1/" --- # Rational Service 42.1: the water supply to the steam generator is not right The steam and combination modes depend on water from the building line. ## What Service 42.1 actually means. The steam and combination modes depend on water from the building line. Service 42.1 reports that the supply is not working correctly. Rational limits the oven to hot air mode until it is fixed. Rational commercial appliance display · also shown as 42.1 What to do when Service 42.1 shows on the commercial appliance ### Kind of code Water, fill and drain Water is not arriving, not reaching its level, not heating or not leaving on time. A dish machine may be short of fill because a supply valve is half closed or its line strainer is clogged, it may drain slowly through a scrap basket full of debris, or its booster may be too scaled to heat the rinse; a combi's steam generator may be scaled or its water treatment exhausted; a washer-extractor may time out on a slow drain. Opening the supply valve, cleaning strainers with the unit off and checking the drain line are fair; a pump, a fill valve, a heater or a leak near wiring is a visit. ### Usually leads to Dish machine repair Undercounter, door-type and conveyor dish machines: tank heaters, boosters, wash pumps, fill and drain valves. ### Shows up as Commercial Appliance Error Code on a Combi, Fryer, Dish Machine or Laundry Display A commercial appliance error code appears as letters or numbers on a combi, fryer, reach-in controller, dish machine or laundry machine display, or as a flashing light or an alarm tone. ### Make Rational A Rational visit is timed after the evening cleaning cycle, when the cabinet is cool and the display can be read without a load inside. ### Source RATIONAL iCombi Pro floor units 20-1/1 and 20-2/1, original instructions for use (US English) Listed in the error message tables of the iCombi Pro floor unit instructions for use (models 20-1/1 and 20-2/1, US English edition). ## Before you book, in this order. Each step comes from Rational's own guidance for Service 42.1 on its commercial appliances. Follow it to the end: the last card says whether this is a visit. 01 Make sure the shut-off on the oven's water line is open. 02 Carry on with dry heat recipes, since hot air mode still works. 03 Book a visit if the valve is open and 42.1 stays. ### Still there? It usually turns into [dish machine repair](https://commercialappliancerepair.center/services/dish-machine-repair/). Book with the code and the model number. ### What not to do Service 42.1 is not the same as Service 43.1, where the internal water supply does not close and water may keep flowing. It is also different from Service 46.1, which shares the wording but leaves cooking fully available. ## What you may notice with it. The commercial appliance problems Service 42.1 tends to arrive with. Answer these at the commercial appliance before anyone is booked. [All problems](https://commercialappliancerepair.center/problems/) Before you call ### [Commercial Appliance Error Code on a Combi, Fryer, Dish Machine or Laundry Display](https://commercialappliancerepair.center/problems/commercial-error-code/) [All 8 causes, cheapest first](https://commercialappliancerepair.center/problems/commercial-error-code/) It also comes with - [**Combi Oven Steam Problem: Weak Steam, Scale or a Dry Cavity**](https://commercialappliancerepair.center/problems/combi-oven-steam-problem/) Problem ### Commercial Appliance Error Code on a Combi, Fryer, Dish Machine or Laundry Display 8 causes, cheapest first Where Service 42.1 usually leads ## Dish machine repair. **Dish machine tank heater or booster element, thermostat, fill valve, float switch, drain valve, wash pump seal or motor, conveyor drive · moderate.** Book a visit [What the job involves](https://commercialappliancerepair.center/services/dish-machine-repair/) ## Rational commercial appliances. A Rational visit is timed after the evening cleaning cycle, when the cabinet is cool and the display can be read without a load inside. [Rational commercial appliance repair](https://commercialappliancerepair.center/brands/rational/) More Rational codes [Service 10](https://commercialappliancerepair.center/error-codes/rational-service-10/) [Service 11](https://commercialappliancerepair.center/error-codes/rational-service-11/) [Service 20.1](https://commercialappliancerepair.center/error-codes/rational-service-20-1/) [Service 25](https://commercialappliancerepair.center/error-codes/rational-service-25/) [Service 28.2](https://commercialappliancerepair.center/error-codes/rational-service-28-2/) [Service 29](https://commercialappliancerepair.center/error-codes/rational-service-29/) [Service 31.1](https://commercialappliancerepair.center/error-codes/rational-service-31-1/) [Service 32.1](https://commercialappliancerepair.center/error-codes/rational-service-32-1/) [Service 40](https://commercialappliancerepair.center/error-codes/rational-service-40/) [Service 41](https://commercialappliancerepair.center/error-codes/rational-service-41/) [Service 47.1](https://commercialappliancerepair.center/error-codes/rational-service-47-1/) [Service 50](https://commercialappliancerepair.center/error-codes/rational-service-50/) [All 15 Rational codes](https://commercialappliancerepair.center/error-codes/#codes-rational) Water, fill and drain on other makes [Alto-Shaam E01](https://commercialappliancerepair.center/error-codes/alto-shaam-e01/) [Blodgett Water Level Error](https://commercialappliancerepair.center/error-codes/blodgett-water-level-error/) [Cleveland LOW WATER light](https://commercialappliancerepair.center/error-codes/cleveland-low-water-light/) [Dexter F2](https://commercialappliancerepair.center/error-codes/dexter-f2/) [Frymaster E33](https://commercialappliancerepair.center/error-codes/frymaster-e33/) [Hatco LO H2O](https://commercialappliancerepair.center/error-codes/hatco-lo-h2o/) [Hobart 019](https://commercialappliancerepair.center/error-codes/hobart-019/) [Miele Professional F18](https://commercialappliancerepair.center/error-codes/miele-professional-f18/) [All 43 codes of this kind](https://commercialappliancerepair.center/error-codes/#family-water) Rational builds this ### Commercial cooking equipment Fryers, griddles, charbroilers, restaurant ranges, convection and combi ovens, steamers, kettles, holding cabinets and toasters, on gas or electric, that make up the hot side of a kitchen line. ## In Rational's own words > The water supply is malfunctioning. [RATIONAL iCombi Pro floor units 20-1/1 and 20-2/1, original instructions for use (US English)](https://hcms.rational-online.com/hcms/v1.7/entity/documents/155435/storage/MTU1NDM1LzAvbWFzdGVyLy8vMTAxNTcwMzIw/download/manual_original_instruction_icombi_pro_20-1_1,_20-2_1_english_usa.pdf) [RATIONAL iCombi Pro floor units 20-1/1 and 20-2/1, original instructions for use (US English)](https://hcms.rational-online.com/hcms/v1.7/entity/documents/155435/storage/MTU1NDM1LzAvbWFzdGVyLy8vMTAxNTcwMzIw/download/manual_original_instruction_icombi_pro_20-1_1,_20-2_1_english_usa.pdf) Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. Listed in the error message tables of the iCombi Pro floor unit instructions for use (models 20-1/1 and 20-2/1, US English edition). ## Rational Service 42.1 commercial appliance repair, where we come out. The same visit in every metro below: the code, the model number, and a diagnosis before any part is ordered. 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Make sure the shut-off on the oven's water line is open. If it comes back, it needs a visit. ### What still works on a Rational showing Service 42.1? Hot air mode. Steam and combination cooking need water, so they are unavailable until the supply is sorted out. ### Could a closed valve cause Service 42.1 on a Rational? Yes, and a shut or half-shut valve is the quickest thing to rule out. If it is open, the problem is inside the oven or in the supply line and needs a technician. ### Why are there several 42 numbers on Rational combis? The manual uses 42.1 to 42.6 in different tables: steam generator, hot air, humidity and care. The exact number tells the technician where to start. --- **[Read on the site: Rational Service 42.1: the water supply to the steam generator is not right](https://commercialappliancerepair.center/error-codes/rational-service-42-1/)** **[Book a visit with CommercialApplianceRepair.center](https://commercialappliancerepair.center/schedule/)**