Ideal Isar - Domestic Hot Water running cold

[deveonspeedking]

Our Isar was providing proper "hot" hot water but on Saturday decided to go on strike. Now we can only get luke warm/cold water. The temp setting on the boiler is quite high, the status display shows "d" and the burner light stays on for a minute then goes out. The water from the taps is, at best, warm - too cold to have a bath!

Central heating works ok and rads get hot within minutes.

Anyone any ideas?

Ta ever so.

 

[gas4you]

Possible blocked plate he

 

[ChrisR]

"he" here means heat exchanger. A common problem. Needs replacing or removing for cleaning.
Also the diverter valves on these fail most weekends, and as it failed suddenly, a more likely one. See if the CH pies get hot when HW called for. Actuator head, DV insert or the whole thing needs replacing.

 

[idealnumber1]

is the hot water intermittent or non existent?

 

[Prof.plumb]

Or dhw thermistor.

 

[gaspro1981]

sounds like the dv cartridge is up the swanny

 

[deveonspeedking]

The DHW flows intermittantly warm then cold. By warm - maybe 20deg C despite the stat being set up high. Altering the stat makes no difference.

The CH runs properly (hot)

 

[idealnumber1]

is d with burner light on all of the time?if so its the diverter
you could try remove the diverter head and push the pin in/out a few times,see if this improves the hot water,if this doesn't work you will need to replace the diverter,at the same time check the plate heat ex isn't blocked

 

[gas4you]

See if the CH pipes get hot when HW called for.

 

[deveonspeedking]

The CH pipes don't get hot when DHW is called for.

When DHW is called for, the burner light comes on for say 15 seconds, then goes out.

 

[kevplumb]

When DHW is called for, the burner light comes on for say 15 seconds, then goes out.

as in it's not losing the heat in the plate hex

cos its full or crud

 

[idealnumber1]

is there any loud noise coming from the pump?

 

[deveonspeedking]

No noises from the pump!

 

[idealnumber1]

then replace the plate heat ex