limited hot water

My Pulsacoil 2000 will only supply limited hot water for one shower, and that is dependent on how long the person takes. During the night i can hear the water heat (makes a boiling type noise). The water that has heated during the previous night will remain hot until it runs out, for example i could take a shower at 10pm and it will still remain hot until it is all used for either bathing, washing dishes etc.

Even with the boost turned on if the cold water runs out there is no extra hot water, it does not matter for how long the boost is left on.

The grey tank which is on top of the P2000 seems to run low on water, so I occasionally fill it up. So far I have replaced the DHW, PHE sensors, and pump, (excuse if the terminology is in correct). Have had various "engineers" out who have been unable to fix it and their only rather unhelpful comment is "the pulsacoils are sh*t).



My confidence in engineers has been knocked, so any help would be greatly appreciated.

just taken the cover off the pulsacoil, the top skel, has some strange greenish foam appearing around the black skel cover it almost looks like its rotten.... any ideas why this would happen? i doubt its a good sign.

The circuit board is flashing two red lights...

the rather large copper element is which has pipes coming out of it is warm to the touch.

i have also just noticed that there is no green light on the part of the boiler where it says "control circuit on"

any ideas guys? help would really be appreciated. i have family coming around soon, and at the moment i only have enough hot water for myself.

As first, you have to be aware the fact, that your Pulsacoil is a night storage Hot water Unit. Means, depending on the size of your unit ( 140, 170, 210 litre) this would be the amount of hot water you will get from one warm up cycle. ( on Economic 7 !!).
As second, your Bath tap is running with about 12 to 18 litre /per minute, a Shower with about 12 l/min any basing will run on 8 l/minute, means for example 10 minute shower with say 14l/min comes up to 140l, is your Pulsacoil an 140l unit so you used all up.
You have now 2 options.
One : change your tariff from eco 7 to eco 10 , this gives you aprox. 5h in the night , makes up 1x full heated tank, 1x in late morning and 1x in afternoon, ends up with about 3 times the hot water you get now.
Two: get rid of the economy 7 and get an 24/7 supply to your " Of Peak" immersion ( may with an manual timer) so you can heat as often your water as you need ( of course you have to pay the higher bill for this)
kind regards
Mario @ Mario's Boiler Service
www.marios-boiler service.co.uk