Vaillant Ecotec 824 DHW temperature

[jakeycrx85]

I have a Vaillant Ecotec 824 combi and the DHW temp maxes out at around 50 degrees even if I turn the DHW temp up to the max of 65 degrees on the controller. Is this normal? I have just put some sentinel X400 in the system to see if this will help.

The boiler is 7/8 years old but the radiators in the house were really old and when I changed them they were full of black water. Could this have clogged the heat exchangers?

 

[AGAS]

where did you put x400 in for the hot water ? how are you measuring the dhw temp ? we have already advised what you need to do regarding your hot water on your other thread ? why did you leave the information out on other thread ? only way we can advise on diagnoses is when you provide full symptoms . as advised you need an rgi to sort your problem ? when was the last time your boiler was serviced ?

 

[jakeycrx85]

I played around with the diverter valve and it is no longer diverting DHW into the CH system. The radiators remain stone cold even after running the bath tap for 10 mins. I also pressurised the pressure vessel as it was empty.

I put the X400 into the towel rad as it has a plug/bung on top so I poured a litre bottle into it. I've only just solved the diverter valve problem this morning so now I'm concentrating on the DHW temp. The boiler hasn't been serviced for a few years now.

 

[dilalio]

Whilst we cannot stop you from removing the cover from your boiler and "playing about" with internal components, do you (or any other diyers reading this thread) happen to know any of the reasons "why" we advise against such activities? Or is it that you just don't care?

 

[AGAS]

what exactly did you do with the diverter valve to stop the problem ? why are you removing front cover ??????? . you need a rgi to sort your problems . how are you measuring your dhw ????????

 

[picasso]

How many litres a minute are you running the tap at ? you can get the water to 60c if you turn the flow rate right down but as its a 24kw boiler you would be getting about 6 litres a minute.

 

[jakeycrx85]

Whilst we cannot stop you from removing the cover from your boiler and "playing about" with internal components, do you (or any other diyers reading this thread) happen to know any of the reasons "why" we advise against such activities? Or is it that you just don't care?

There is an FAQ at the top of the forum telling you how to pressurize the pressure vessel. This involves removing the front cover does it not?? If it really is such a big no no to remove the front cover then why is the FAQ page on this forum telling you do so? If you disagree with it that much maybe you should leave the forum and find one that advises against removing the front cover. I really don't understand why people like you have to get so worked up about things. I'm actually a qualified E/I/M engineer by trade so I'm not a complete idiot. I wouldn't touch anything to do with the gas supply but I really can't see what harm you are going to do looking at the plumbing side of things.

what exactly did you do with the diverter valve to stop the problem ? why are you removing front cover ??????? . you need a rgi to sort your problems . how are you measuring your dhw ????????

I'm removing my front cover because there is obviously a problem with the boiler. I wouldn't fiddle with the gas side of things but I've seen plenty of threads about manually working the diverter valve which is what I did. I worked the plunger back and forth with a pair of longnose pliers and then cycled the CH and DHW. I also adjusted the position of the motor that drives it. I measured the DHW temp using the thermocouple on my Fluke and also using parameter d.3 in the first diagnostic level. They are within one degree of each other.

How many litres a minute are you running the tap at ? you can get the water to 60c if you turn the flow rate right down but as its a 24kw boiler you would be getting about 6 litres a minute.

It maxes out at 8 litres per minute and thats when the DHW temp is at 50 degrees. If I turn the tap down to 3 litres per min then it achieves 65 degrees. As I start increasing the flow from 3 litres per minute then the DHW temp then starts to drop off. Would you say this is normal for a 24kw boiler?

 

[dilalio]

There is an FAQ at the top of the forum telling you how to pressurize the pressure vessel. This involves removing the front cover does it not?? If it really is such a big no no to remove the front cover then why is the FAQ page on this forum telling you do so?

Room sealed appliance... That seal is broken when you remove the cover... Like I said, can't stop you but you don't know why it's advised against... Just make sure the seal is in tact.

I wasn't looking to start a flame war... For your understanding... People "like me" don't get worked up, it's merely that we give a ****!

 

[jakeycrx85]

There is an FAQ at the top of the forum telling you how to pressurize the pressure vessel. This involves removing the front cover does it not?? If it really is such a big no no to remove the front cover then why is the FAQ page on this forum telling you do so?

Room sealed appliance... That seal is broken when you remove the cover... Like I said, can't stop you but you don't know why it's advised against... Just make sure the seal is in tact.

I wasn't looking to start a flame war... For your understanding... People "like me" don't get worked up, it's merely that we give a ****!

The cover has been removed before by a BG engineer when I first moved in. When I reinstalled it I made sure it was secured on the 2 lower clips and have reinstalled the M6 screw at the bottom of the boiler cover. I understand your concern but there are some idiots in the trade as well. When I had the kitchen done the so called "RGI" managed to push the analogue pressure gauge into the boiler when tapping it to check the pressure. He also exploded the bricks on the outside of the house when installing a new overflow pipe. Absolute idiot. He was also scared off by the external stopcock because it had filled with mud and crap. He said we'd have to call the water company in. After he left I proceeded to lie on my front for half an hour and dig all of the crap out by hand. He looked a bit surprised when he came back the next day and I told him he could now turn off the stopcock.

I live in the house with my partner and 6 month old baby so I wouldn't dream of touching anything to do with the gas side of things. I'm quite happy to do the plumbing side of things though. I'm happy and competent enough to change radiators, drain/refill/bleed the system etc.

So would you say a DHW temp of 50 degrees at 8 litres per minute is normal on a 24kw boiler?

 

[picasso]

Depends on the incoming temp of the cold water, combis flow rates are rated at a 35c rise so if the incoming water is 10c and your hot water is 50c thats a rise of 40c, the 24kw ecotec is rated at 9.5 ltr per minute at 35c so your 8ltrs per minute aint far off the mark.

 

[jakeycrx85]

Depends on the incoming temp of the cold water, combis flow rates are rated at a 35c rise so if the incoming water is 10c and your hot water is 50c thats a rise of 40c, the 24kw ecotec is rated at 9.5 ltr per minute at 35c so your 8ltrs per minute aint far off the mark.

Good information. Thanks for that. It looks like I'm worrying for no reason then. The main reason I want to increase the DHW is for the shower. I have a Grohe thermostatic bar type. I like a really hot shower.

I've just replaced the cartridge thinking it was faulty but it wasn't. I'm guessing if I throttle back the cold water pressure to the shower a bit that should increase the temp on the shower?

 

[dilalio]

Could you not just adjust the tab on the thermostat of the shower valve so that it allows more hot in, than cold? You can then set it's safe point to be higher than normal, allowing you to swing it round to even hotter for your personal pref.

 

[jakeycrx85]

Could you not just adjust the tab on the thermostat of the shower valve so that it allows more hot in, than cold? You can then set it's safe point to be higher than normal, allowing you to swing it round to even hotter for your personal pref.

I just wound the temp dial to the max stop then removed the dial and got about another 8th of a turn out of the thermostatic valve behind it. It's nice and hot now!

 

[dilalio]

I just wound the temp dial to the max stop then removed the dial and got about another 8th of a turn out of the thermostatic valve behind it. It's nice and hot now!

Yeah, that's what I meant but you put it better

 

[jakeycrx85]

I knew what you meant! I've had to warn the Mrs to back the temp right off next time she has a shower as its a lot hotter now!

Thanks for the help Gents