Problem with hot water

BnB

I have a problem with the hot water in our house. I believe (But I could be wrong) that the water is getting heated but for some reason it is not being delivered to the taps/showers etc (If that makes sense)

When I heat the water (with the oil or with the immersion) and I then turn on the shower, I will have a blast of roasting water for maybe 10 or 15 seconds but then it will go to barely luke warm.

We have an oil burner which we usually use to heat the water. We also have solar panels connected to the system .

We cleaned out the hot press lately (where all the workings are) and I think it could have been something that was knocked.

I did find a Thermostat (This one: http://www.taylorparts.ie/firebird-istat-dual-thermostat) that had been knocked off the middle of the water tank. I re-fitted it on and it doesn't seem to make any difference.

There is a separate digital thermostat which seems to be connected to the top and bottom of the tank which is used for controlling the solar panels and that shows a temp of nearly 60 Deg at the top of the tank and 49 deg at the bottom which I would have though shows that I have a full tank of hot water.

I can't see anything obvious in the hot press that could be causing the problem.

Anyone have any idea what I should be looking for ?

Thanks in advance.

BnB

OP Here - Just some further information on this that may or may not be relevant.

Our system is pressurized from a pump in the garage. The only water in the house that doesn't go through this pump is the drinking water to the kitchen sink.

Pete67

Is there a thermostatic mixing valve installed at the outlet of the hot water tank - often part of a solar install to prevent scalding - if so, could it have been adjusted inadvertently?

BnB

Hi Peter. Found the problem this evening and it was exactly what you suggested above. There is a thermostatic mixing valve at the outlet of the hot water tank which mixed the hot water with the mains water. Apparently a safety measure to protect against scalding.

I cut off the mains water going into this and it solved my problem. Even before it went completely a week ago, the hot water used often act a bit strange so I think now that this valve never really worked properly.

Pete67

BnB wrote: »

I cut off the mains water going into this and it solved my problem. Even before it went completely a week ago, the hot water used often act a bit strange so I think now that this valve never really worked properly.

It should not be supplied with mains water - it should be supplied with cold water from the same pump as the hot so that both hot and cold supplies to the mixing valve are at the same pressure.

You should get it fixed / replaced as with solar heating the water temperature can get hot enough to cause a severe burn.

BnB

Sorry - I got my terminology wrong. All the water that comes into the house (apart from the drinking water) has come through the pump (which is in the garage) so when I said "mains" water it is actually the output of the pump and the same as the input to the hot water tank.

And yes - I will get it sorted. Now that I know what it is, I can turn it on and mess around with the Thermostat and see if I can get it working properly. If it was just myself I'd probably just leave it off but I wouldn't chance it with young kids.