Pulsacoil III and Horstman 7

[haccor]

Hi there,

I was wondering if anyone can help.

I have just moved in to a rented flat, and the hot water stopped working on Saturday. We have reported to the landlord, but hoping with there being 2 x immersion heaters I can program something temporary.

I have a pulsacoil III with 2 immersion heaters and a Horseman 7. One of the fuse blew, I believe for the boost immersion, leaving the economy 7 immersion working. I replaced the fuse, boosted it for a while, but the fuse went again. I amusing it's shorting when reaching a certain temperature (?), but letting the fuse do it's job, so won't replace again 'till it's looked at!

Surely with the remaining immersion i should be able to get some hot water? Bizarrely, I seem to get some very tepid water in the morning, so it's doing something, but never hot! Still too cold to shower in!

As a side note, I have just seen the program and it seems a bit excessive! Have a feeling this must be costing me a fortune!

Boost programme 1
ON 7.30am
OFF 10.00pm

Economy 7 Programme 1
ON 10.30pm
Off 9.15am

Economy 7 Programme 2 and 3
Both set to 12:00 on and off, so presumably off!

Question is (sorry so long winded) can I do something to give us temporary hot water until the other immersion is fixed (replaced)?

Any help MUCH appreciated.

Thanks

 

[hertsboilers]

Bottom one is doing some heating towards hot water, but not doing enough?

Check the temp setting on the immersion heater? It should be at 65C or so.

 

[picasso]

Your immersion should be set to 77c and check to see if the pump is running when you open a hot tap, the mixing valve is a common failure on these.

 

[flameport]

I have a pulsacoil III

How unfortunate. Best start looking for a new flat now.

The Pulsacoil is a thermal store - water in it is heated to a high temperature by the immersion heaters, and kept that way all the time using expensive electricity.
When hot water is required, cold water from the mains is passed through a heat exchanger and hot water from the store is pumped through the other side, resulting in the cold water being heated up. As this would be far too hot to use, a blending valve then mixes the just heated water with more cold from the mains, and that is what you get out of the tap.
Some models can also do a couple of tiny radiators by circulating water from the store through them using another pump.

Whether it works is therefore dependent on the store being heated properly, the pumps, temperature sensors, heat exchanger, valve and controller board all working perfectly.
When one or more items fail, you get nothing.
If only the boost heater is working, it will only heat the upper part of the store, and you will get little or no hot water.

Due to the excessive complexity of the device, failures are inevitable and will happen often. The parts cost a fortune assuming you can even get them, many people will not work on these contraptions and the only sane thing to do is to rip it out and put a normal hot water cylinder in.

As a side note, I have just seen the program and it seems a bit excessive! Have a feeling this must be costing me a fortune!

That's the only certainty with these things - they use the most expensive fuel available (electricity) to heat water in the most convoluted way possible.