Hot water lukewarm.

[bluesmartie]

Hi, I've a Ideal Isar. Recently, I've noticed the a lack of heat when running the hot water. The heat seems to come in waves, and it never gets any hotter than lukewarm, you can keep your hand beneath the tap without any discomfort. When the hot water is running the central heating doesn't appear to work, the rads become faintly warm. The central heating works wonderfully otherwise. I've recently added a Salus RT500RF wireless thermostat. The thermo seems to be functioning fine, so well, the house takes no heating now, this couldn't be the problem, could it? I've also checked the hot water dial on the boiler, it up to max. Tried Googling the symptoms, but every fault seems to be focused on a complete lack of hot water, or the rads coming on when the water is running. My issue is the opposite, really. Can anyone help.

TIA

Bluesmartie

 

[gigz]

When the rads are cold, turn on a hot tap and feel the copper pipe on the left hand side of the boiler, if this gets hot then your diverter cartridge is passing and will need replacing. If it doesn't get hot try closing the tap down to restrict the flow (not too far down though) if it starts getting too hot to touch and the blue flame light goes out on the boiler its more than likely the plate heat exchangers blocked.

 

[bluesmartie]

Hi, just an update. I got the repairman out, and they said it was the heat plate. They've replaced the heat plate, and I have hot water again. However, I still can't run the heating and the hot water, at the same time. The boiler simply stops the heating, and I get tepid water from the taps. Once I turn the hot tap off, the boiler goes silent, then I hear it fire up, and the pump start for heating. The repairman was no help at all, simply blaming my shower for it. I turned the shower's isolation valves off, and it's exactly the same. I don't understand how the shower could possibly be causing the boiler to do this. Any help would be wonderful.

TIA

 

[picasso]

You cannot run the heating and hot water at the same time on a combi, if you turn a tap on all the power of the boiler goes to heat the incoming cold water, turn the tap off and the boiler goes back to heating the rads, do you have hot water or not ?

 

[bluesmartie]

Hi... Thanks for the reply, and clearing up the heating going off, I never realised this to be the case. I've clearly never noticed this happening, in the past. Yeah, I'm getting piping hot water, when the heating is off. When it is on, the water temp is massively reduced, I can keep my hand beneath the tap, without discomfort.

 

[gigz]

Did they check the diverter valve ? With the heating cold, turn a hot tap on and check the left hand pipe coming out of the boiler, it shouldn't get hot. If it does you need a diverter cartridge.