what is this and am i getting ripped off?

[MROOD]

apologies, im new to this so Ive had a quick youtube/google for knowledge.

I have a heatrae megaflow boiler in a all electric flat



looking at the boiler it has 2 thermostats elements immersion as above

last year the boost switch which gives me extra hot water failed so i ignored it, the boost switched on gave extra hot water when needed.

Last week the 2nd thermostat stopped working, so no hot water, So i called a plumber and paid a £90 call out fee, he had a look and quoted me £700ish parts labour, 2 thermostats or immersions elements thingy and boiler drainage.

I said id think about it, as i thought it was very expensive . I bought a thermostat online from you tube knowledge for 25.00 quid its a original or oem part.

I fixed the thermostat in the top spot of the boiler, i believe this controls the boost function.

But when the hot water gets hot, water squirts out from the thingy and into a open pipe, so I have to switch off the boost and use the hot water to stop the squirt.



this is the thingy and you can see water in between the ********




can anyone tell me why hot water come out and if that is normal? if it is not normal then what do I need to do to make it normal,

Im thinking change the thermostat from the boost and place it in the bottom slot, ?

[MrShamus]

To fix the water coming out of the pressure release valve, you will need to follow the instructions attached to the side of the cylinder (steps 1-5 in your first image). You will find that you need to do this periodically to replenish the air gap contained within the cylinder.

[darrendobson]

700 is expensive and 90 callout is robbery.

Get another quote. should easily get this done for £200-300

There is a reason you need to be qualified to work on unvented cylinders. They can be very dangerous and should be serviced yearly to check all safety devices are working correctly.

[ianh100]

I have to agree with that comment, replacing a thermostat is OK but you really dont want to start doing anything that could disable or bypass the safety features installed by the manufacturer. I had issues with a similar system, this video makes it very clear why you need to give these systems a lot of respect! https://www.youtube.com/watch?v=61uDmQF5I2E