An expert who has achieved level 2 by getting 100 points
An expert that got 5 achievements.
An expert whose answer got voted for 100 times.
An expert who has written 50 answers of more than 400 characters.
Re: Rennai 551 FA-P Never fully shuts off
Is there a chance there is a draft around the room temp probe? It is down low on the right side of the heater. If there is a draft the room sensor is fooled and keeps running the unit. You should be able to prove the room sensor by putting your hand over it after the stove has been running for a while. This should shut the stove down. If not there is a problem with the room sensor.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
If it's thermostatically controlled, if shuts off the burner when it reaches the set temperature. Is the pilot flame going out too? These heaters require a certain amount of fresh air to operate properly. If the oxygen level gets too low, it is designed to shut off completely for your safety.
It always helps to add the model number of the item you want help on. However if it's like the newer units, the fan operates whenever the heater wall has reached a high enough temperature and shuts off when the heater cools off. It is not wired into your thermostat or electrically wired to the heater. It does that with a temperature driven fan switch in a little junction box mounted to the heater. Normally when that box gets hot because the heater is on the fan comes on, when it cools off the fan goes off. The junction box will have an ac cord coming out of it. If this fan switch junction box is not properly mounted it could be getting cooled off when the fan starts and then shuts itself off. After it heats up again it starts the fan. The other possibility is the temperature based fan switch is failing and needs replacement. See link.
What is the fuel you heat the boiler with?-- Oil or Gas?
Does the flame ignite initially, and then sputter out- or positively SHUT off, like a valve is closing?
Is there a High temperature (or Pressure) limit being reached, to shut it off?-- or other controls, like: Low Water, Hi Temperature plenum switch? -- can you do some trouble shooting, and get back with us, so we can help you better?
Sounds like the thermocouple needs changing. This is the flame failure device, they can burn out after a few years. Recommend getting a technican to fix it but you could ask him to make sure he has a thermocouple for this model on his first visit to save paying for two calls.
I had the same problem with this unit and had the heater serviced which fixed the problem. The problem is caused by the pilot flame not being big enough to keep the thermocouple hot, so the heater thinks the flame is out and it turns the gas off! The thermocouple is effectively a switch that is on when hot and off when cold. The pilot flame is supposed to keep it hot, so its on and the main burner will get gas. When its off (ie cold) gas is blocked from the main burner for safety reasons! This manual is for a very similar heater: http://www.rinnaisales.co.nz/tradesmart/rinnai2/pdfs/service_info/171.pdf