Valiant 242 DHW water issue

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Hi
I have a valiant 242/1 boiler , less than 5 years old. My issues is that when i turn the hot water tap on i get hot water instantly but when i turn it off an immediatley turn it on again i find that i only get cold water. i have to then shut the tap off and wait sometime 10 mins before turning the tap on and the hot water light on the boiler comes back on. i had a look at the microswitch the other day when this happened and i noticed that the actuating lever was going down onto the microswitch but doesn't look like it was depressing it far enough. when i depress the lever above the microswitch manually by an additional millimeter the hot water comes back on. Please note that the microswitch /Diaphram were recently replaced by a plumber when DHW stopped completley. do you think he has has not put the lever in the correct position properly ?

The other thing i only noticed that the water pressue which should be 1.5 , i've recently every couple of days have had to top it off. Something i never needed to do before the plumber came in and stripped the boiler to find the issue and then fitted in the microswitch + diaghpram. Not sure why this is the case now ? any ideas?

 

[Rob]

Microswitch is adjustable! Just loosen the small screw.

 

[Agile]

Hi
I have a valiant 424/1 boiler , less than 5 years old.

I thought that the 424 was a heat only boiler but it seems that its actually a combi.

Can Dave briefly describe if its just an open system version of the 824 ?

Tony

 

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sorry got the model wrong its a vuw 242/1 E. I'll check to see if the microswitch is adjustable , hopefully should solve my issue ...

Any idea on the Water pressue ?

 

[gas4you]

Yes Tony the 400 series is just an open vent heat only boiler that can be made pressurised as well.

There's not a 424 though.

 

[ghplumb]

Were all the small copper tubes cleaned out & the chambers in & onto the Diaphram clear as well

check both ends off the small copper tubes

 

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All fixed, I called the insurance up and forced them to send someone more reliable. They put a bit of a fight but finally caved in and i got someone from Valiant. The guy came looked at my issue and completley replaced the diverter valve + mico-switch - told me for things like this it's better to replace them , you can change the diaphram etc to save money but if something else is wrong its just another call out. (i had gone through my insurance 5 times on the same issue). He also replaced the heat exchanger. Its been running brilliantly ever since + i now get really hot water upstairs that i now have to open the cold tap . Thanks you to everyone on the forum who tried to help