Boiler hot water flunctuates

[Elsa TLC]

Have you stood at the kitchen tap with your hand under the hot water fir a few minutes?

 

[Johntheo5]

To rule the boiler out, next time (of if you want to do a test before putting the shower on, just open a hot tap slowly to get the boiler to cut in, then open it a tiny bit further to increase its flow a little, then start the shower and see does it run continuously without running cold. If it does, then shower non return valves or/and thermostatic cartridge suspect, IMO.

 

[CountryFan]

I'm going to bump this thread as no one has seemed to bothered to reply.

Anyone?

Jeez, only logged yesterday. Plus one for checking the shower valve. Isolate the cold underneath and run the hot side of the shower and try other outlets tooz shouldn't get any water out. Doubt it's the flow sensor unless it's not seeing a demand, could also be blocked plate heat exchanger, canoe filter et al.

 

[gas112]

Thanks but what would be wrong with the shower itself and what part would need changing and say if the other taps were affected too what would be wrong with the boiler?

try actually telling us if its faulty at the other taps

 

[TAMD8389]

Jeez, only logged yesterday. Plus one for checking the shower valve. Isolate the cold underneath and run the hot side of the shower and try other outlets tooz shouldn't get any water out. Doubt it's the flow sensor unless it's not seeing a demand, could also be blocked plate heat exchanger, canoe filter et al.

Thank you for the reply. I don't think I would've seen a reply if I didn't bump the thread.

Question - What does the shower cartridge do, and if it has failed, how would it pursue the fault which I am experiencing right now?

 

[TAMD8389]

Have you stood at the kitchen tap with your hand under the hot water fir a few minutes?

I haven't, but if I do, and I experience the same problem, would that prove anything worthwhile?

 

[Elsa TLC]

I haven't, but if I do, and I experience the same problem, would that prove anything worthwhile?

If the tap goes hot then cold after the initial start up and fluctuates there on, then id be looking at the boiler.

 

[CountryFan]

Thank you for the reply. I don't think I would've seen a reply if I didn't bump the thread.

Depends, but the little bell at the top usually states notifications.

Question - What does the shower cartridge do, and if it has failed, how would it pursue the fault which I am experiencing right now?

If it's a thermostatic cartridge, then this is what helps to regulate the temperature mixing hot and cold. If it's failed or failing then going hot and cold can be a symptom, as can a restriction, so test with shower head removed, if still the same then check without the hose. If this still persists, then either the cartridge or boiler fault. However, if only shower affected then unlikely (but not impossible) the boiler.

You mentioned an ecotec boiler - usually equipped with a display PCB, run the shower and go to the display and note the temperature reading and also press the I button and report back after trying all these suggestions including the above

 

[Rodders53]

If I increase the output of the shower mixer it turns hot back again.

Flow rate too low for the selected mixed temperature means the combi cycles on/off? Shower with the output flow rate higher all the time? Or were you meaning something else?

You might also check/service the shower mixer valves: inlet filters may be restricting the hot flow due to limescale build up for instance.

 

[TAMD8389]

Hi, on further investigation, I have read about thermostatic mixer valves, and I think the problem can be with the shower? I think the mixer is cutting the hot water when the set temperature is reached on the mixer. Could someone tell me if this is right? There are two rotary knobs; one controls hot water and the other has degree markings on it. I don't use that one, but I'm sure it serves a purpose.

Thank you folks.

 

[TAMD8389]

No one, not even one, has replied back to my message.

I see.

 

[CountryFan]

Must have missed it as I can get several alerts. No, I don't think it's to do with reaching temperature as they're designed to stay lit whether you shower for 5 minutes or 65 minutes.

Have you carried out any testing recommended and posted results?

I see.

 

[TAMD8389]

Must have missed it as I can get several alerts. No, I don't think it's to do with reaching temperature as they're designed to stay lit whether you shower for 5 minutes or 65 minutes.

Okay. That doesn't explain the reason why there is two knobs and if you say one of the knob, not the hot water one, is NOT used to reduce the temperature of the hot water, then why is there degree markings on it? Doesn't that imply there is a thermostat inside the shower and its actually letting cold water in to meet the demands of the parameters set?

Have you carried out any testing recommended and posted results?

I have not, and I believe I do not have to because I'm 90% sure the shower is the culprit, and I cannot envisage me standing at the tap for a good thirty minutes.

 

[CountryFan]

Okay. That doesn't explain the reason why there is two knobs and if you say one of the knob, not the hot water one, is NOT used to reduce the temperature of the hot water, then why is there degree markings on it? Doesn't that imply there is a thermostat inside the shower and its actually letting cold water in to meet the demands of the parameters set?

One should be to turn the shower on and off/alter flow rate the other temperature. The thermostat would be blending hot and cold water to the temperature set by the knob. If the thermostatic cartridge has failed or cold is overpowering the hit then this needs to be checked out.

I have not, and I believe I do not have to because I'm 90% sure the shower is the culprit, and I cannot envisage me standing at the tap for a good thirty minutes.

Ok, if you believe the shower is the culprit then repair or change it. I don't recall asking you to stand at the shower for 30 minutes. @gas112 asked if it was happening at other taps.

 

[Elsa TLC]

One should be to turn the shower on and off/alter flow rate the other temperature. The thermostat would be blending hot and cold water to the temperature set by the knob. If the thermostatic cartridge has failed or cold is overpowering the hit then this needs to be checked out.

[B]@gas112[/B]

I can see your point.