vaillant ecotec pro 28 - water temp not hot enough

[robert k]

HI, basically I have had the boiler for 5 years and its never been serviced but never had any problems and the rads water is very clean, when we first got the boiler the hot water temp was set at 55oc and the the shower and tap water was scorching hot but gradually the temp of water has got colder and even with the water temp turned up to 65oc the water out the taps and shower is just about hot enough, i measured the water temp and both the shower and taps were 39oc, I know the plate heat exchanger is not blocked as I had it off and cleaned it even though it was very clean anyway and also fitted a new pressure sensor, the display shows the temp getting up to 65oc but its just not coming out that hot, any ideas what it could be? any help would be much appreciated. Thanks.

 

[Chuck]

HI, basically I have had the boiler for 5 years and its never been serviced

Get a qualified engineer to service it and mention the fault at the time you make the booking. Should be a straightforward fix for someone who knows what they are doing.

 

[Knappers]

Unfortunately on that boiler, taking the cover off is breaking into a 'gas way' and so we (qualified gas engineers) can't give you advice on this.
On other boilers the compartments are separated so its more possible.

 

[moonlight]

It could be the shower letting by.

 

[John.g]

Just get out your bucket and 1 litre jug and hold the bucket under the shower/tap for exactly 1 minute and measure it with the jug. Assuming 28kw output and 6C mains temp then the flowrate should be 12.2 LPM at 39C, that will narrow down the problem once you measure that flowrate and temperature.

 

[robert k]

Just get out your bucket and 1 litre jug and hold the bucket under the shower/tap for exactly 1 minute and measure it with the jug. Assuming 28kw output and 6C mains temp then the flowrate should be 12.2 LPM at 39C, that will narrow down the problem once you measure that flowrate and temperature.

Hi john thanks for your reply, so i ran the hot water for 1 minute and got 4.6 litres and the temp was 38.7oc this was just about the same for both the tap and the shower?

 

[robert k]

Hi john thanks for your reply, so i ran the hot water for 1 minute and got 4.6 litres and the temp was 38.7oc this was just about the same for both the tap and the shower?

also something else i noticed is on other eco teec pro boilers ive seen there is a temperature thermostat on the hot water pipe and i looked at my boiler as i thought it could be to do with that and I dont have one on that pipe, should i have? is it located somewhere else? I have added a pic. cheers.

 

[John.g]

If the DHW temp is settable then would think that the HW outlet would have a sensor but its possibly derived from the boiler flow/return temps and other parameters from the boiler, but if set to 65C then the boiler water flow temperature must be = or > 65C as well.
Your measurements show a boiler output of 10.5 kw, if the temp was 65C then the boiler output should be 18.9 kw at 4.6LPM.
Irrespective of the temperature why is the shower only flowing 4.6 LPM?, if you turn the setting to fully cold (with boiler DHW temp set to minimum) is the flow rate still only 4.6 LPM., if it doesn't increase then suggests some restriction in the boiler ( but should still give 65C temperature)

The only thing you can check is from the menu, most boilers can have the boiler range rated on CH but this shouldn't affect the boiler output on DHW.

 

[ShaunCorbs]

Closed due to op and diy gas