Baxi 5114725 Duo-Tec Megalow Platinum Thermister NTC Temperature Sensor

We have a fairly old combi boiler which has been mostly faultless over the years. Recently whilst showering, the water would start off hot and intermittently lose temperature, going freezing cold. After some research, the temperature stat on the hot water side seems to be the main cause so ordered this, particularly as it’s a cheap and easy thing to try. Fitting took a whole 10 mins and was very easy. The process I followed was… 1. Switch of boiler at mains. 2. Switch off mains water and run both hold and cold taps till the water stops. 3. Remove boiler panel. 4. Locate stat on 3 way valve and remove plug. 5. Use 13mm spanner to remove faulty stat. There is a metal washer which may be still attached to the valve so also remove. 6. Insert new stat making sure not to over tighten. I also used a very small amount of PTFE tape to ensure no leaks. 7. Re-attach plastic plug and replace boiler cover. 8. Ensure all taps are switched back to off. 9. Switch mains water and boiler back on. 10. Bleed air out of taps and run hot water. Hopefully your hot water comes back on and you are fault free. I am a certified electrician so was comfortable doing this repair. Please DO NOT attempt if you don’t fee competent to do so. I am in no way responsible if you follow my instructions and damage your boiler. It is a very quick and cheap fix and saved us from calling out a plumber. If it didn’t work and had the potential to be a larger problem, then we’d obviously call out a professional. Happy that it’s worked and saved us a lot of money.

Worked well, fitted easily on Baxi Megaflow 28 HE (not Combi). Easy to fit, no need to shutoff water the supply temp probe has a well in the pipe so there is no water in there.

Solved the fault. Still all good . Good quality product

As discrived

Great - did exactly what it needed to do

Simple switch over after E20 fault code and tested old part which showed open circuit. Simple inexpensive boiler fix compared to £80 call out and £15 part. No water or gas involved in this repair, just a simple unscrew and replace!

The product arrived very quickly, quicker than advertised. The product itself was an easy fit, and my boiler is back working again, all for less than £4! However, although the part is the correct part number for my boiler it does not appear to be calibrated correctly for it and hence I have had to turn down the boiler temperature to compensate. The water temperature produced is approximately ten degrees C greater than the setting on the boiler dial. I can live with it with the workaround, but the product is clearly not perfect hence no five stars. I have yet to see how long lasting the product is - it is quite a lot cheaper than the OEM part from Baxi, so we shall see! All in all, satisifed, but could be better.

Hot water temp was up and down, combi wouldn't hold a steady temperature while taking a shower. Watched the boiler and despite the dhw being set to 65°, would rocket past and trip the burner off, temp would then drop and the burner would kick back in. I had previously replaced the plate heat exchange and the diverter valve guts so was pretty sure the fault was elsewhere. Turns out this little part will get limescaled up and stop sending the temp properly. Dead easy to swap out, isolate the boiler, close the water inlet and open the hot tap. Keep a pot handy to catch the little bit of water that will leak out, disconnect the electric connector from the top and simply undo the nut, and swap for the new part.