Hot water booster for my unvented cylinder doesnt seem to work after about 5 pm?

[JohnSey]

Hi, I have an OSO direct 20 RD Unvented water heater, with 2 elements; the bottom one heats overnight using economy 7, and the top is a booster to be manually switched on when a bit of extra hot water is needed.

The problem is that after about 5 PM the booster element does not come on when I flick the switch, however, before this time it does appear to work. Obviously, this is majorly frustrating as its usually in the evening when I may need a bit more hot water.

Any ideas on whats going on here?

 

[joni os]

Suspect boost is wired to restrict high tariff usage.

 

[townfanjon]

Are you turning it on when the cylinder is already hot , obviously it wont 'need ' to come on .

 

[JohnSey]

Thank you joni os, thats a good point, it may have been wired like that in the past. I guess I'll have to get an electrician to take a look at some point, thanks for your advice!

 

[townfanjon]

Suspect boost is wired to restrict high tariff usage.

Must be a 'london thing ' that lol , boosts are always viewed as 'backup ' up here .
If Theres somthing wrong with off peak and the cylinder can always be heated via the boost / back up

 

[JohnSey]

Townfanjon, no, I was out of hot water the other evening and could really have done with a top up, but wouldnt come on....however, I had checked it was working OK previously in the day

 

[townfanjon]

Thanks john, sorry I had to ask. Is your boost on a switch or part of a programmer ?

 

[JohnSey]

Its just on a switch townfan jon

 

[townfanjon]

Quick test by a sparkie should test if there is , or isnt a live. Depending if you are confident you could turn the switch off , remove the immersion heater cover and see if an overheat has operated , normaly a resetable button .
Failing that its a sparkie or one of us, the problem with sparkies are if the immersion heater has blown they wont take the job any further. Then you end up getting hold of a G3 regestered plumber / heating engineer .

 

[JohnSey]

OK townfanjon, thank you for your advice, I will look into getting someone to take a look soon,