vaillant ecoTEC plus 637 CH 2.9 bar

[zwobott]

hello

I'm a newbie, don't really know much about plumbing nor CH etc.
As mentioned in my earlier post, I live in a rented house (4 beds, box room, living room and kitchen). We've been using vaillant ecoTEC plus 637 for HW and CH;

Some time ago, I had set CH temperature at 50C, but when we realised that heating is not reaching the top floor and some bedrooms' radiators are only warm, yesterday evening I raised the boiler's CH temperature to 60C. Instantly it has become warmer/hotter, and even in the living room I was forced to turn my thermostat down from usual 5 to 2 (due to the amount of heat being delivered).

But what I have noticed today is that on the boiler's display there is ''2,9 bar'' flashing and the indicator is very close to the red on the gauge. As soon as the CH cycle had finished, I lowered CH temperature to 55C and soon after the ''2,9 bar'' stopped displaying. Meanwhile, I spoke to a friend of mine, not a plumber, who said that this is unusual, everything should be ok if only it will not exceed 3,0. He said that I could de-pressurise the system by letting some water off from one of the radiators (which I have done).

The system so far worked perfectly, there are no error codes on the display.


Should I be worried, call en engineer, or just keep eye on the boiler and let some more water off if needed ?


Thank you for replies

 

[Simon F]

as the water heats up it expands and so increases the pressure. what does the pressure read when the system is cold?

 

[zwobott]

CH cycle finished an hour ago at 6.30pm, it is now 7.30pm, but HW is now on, and ''2,9 bar'' is flashing again. What I have noticed is that when the boiler is off, I mean when neither CH nor HW is operating (HW reached desired temperature, CH's cycle is not on), then the pressure drops a little and ''2.9 bar'' is not flashing, but when for HW turns on, the ''2.9 bar'' is back again. Could this be too much water in the whole system ?

 

[CES]

You need to drain some water out of your system to lower the reading on the pressure gauge. It should be approx 1.5 bar (or about halfway between where 10 and 11 would be if it were a clock face). As explained above when the temperature increases the pressure increase due to a lack of expansion capacity within your expansion vessel. It could have lost its charged, be undersized for the size of your system or burst. This will be best checked by a competent engineer.

 

[zwobott]

I drained some water out of the system, not much maybe 200 ml and set CH temperature to 60C and HW 55C; but shortly before CH turns itself on, I have completely switched HW off and waited for about 10 minutes; then switched the HW back on and CH turned on also; meanwhile indicator on the gauge dropped to around 10.30 (if it was a clock), in the middle of the grey area and now, 35 minutes of CH being on it moved upwards slightly, staying at around 11 o'clock

is there any way I can check the actual pressure on the boiler ?

 

[CES]

The system pressure should be set when cold. You can check the actual pressure by pressing the (-) button.
You will need to drain a bit more water out to lower it down but I think your problem is the expansion vessel needs either replaced or recharged which is a job for someone competent to do so as it needs to be charged when the boiler is drained down.

 

[zwobott]

well, everything seemed to be fine, until I decided to raise temperature of CH from 50C to 60C. It had become hot, hot, so I had lowered the thermostat in my bedroom, which is a kind of indicator for me, from usual 5 to 2, and had the same effect/temperature in the room as before; I remember that the pressure indicator had been at usual 10.30-11.00 o'clock, until I moved/set CH temperature upwards yesterday evening; at the moment, after 1 hour and 25 minutes of CH and HW being on, the system reads pressure at 2,8 bar, (indicator is at about 11 o'clock, about), it still has got about 20 minutes of working time, so we'll see how it goes;

 

[CES]

When it was at 50 oC the pressure was lower, when you increased the temperature then you made the water hotter which causes it to expand more. As you have nowhere for the water to expand to, the pressure increases accordingly. You need to correct the fault with the expansion vessel or it will end up causing further problems down the line. I would get a professional in to sort it out.

 

[zwobott]

what I'm gonna do first is to check the pressure indicator when the system is off/cold, if it is between 1.00-2.00 bar, then according to the manual which I am studying patiently now,everything should be fine, if not then first I will let some more water off the system, if this won't help, I'll call a professional; at the moment, 5 minutes after the CH cycle has come to an end, pressure is at 2,6 bar;

 

[CES]

I don't mean to be cheeky but regardless if your pressure is between 1 and 2 bar when cold, you have no or little charge in the expansion vessel which is evident due to the increase in pressure when hot, so everything will not be fine. You will need to get the expansion vessel checked otherwise it will rise through time and will eventually lift the safety valve and you will wake up to no heating or hot water due to no system water pressure. Similarly if you let too much water out then when the system cools you will not have enough system pressure for the boiler to operate.

 

[secret squirrel]

I don't mean to be cheeky but regardless if your pressure is between 1 and 2 bar when cold, you have no or little charge in the expansion vessel which is evident due to the increase in pressure when hot, so everything will not be fine. You will need to get the expansion vessel checked otherwise it will rise through time and will eventually lift the safety valve and you will wake up to no heating or hot water due to no system water pressure. Similarly if you let too much water out then when the system cools you will not have enough system pressure for the boiler to operate.

Bouncing your head off of a wall, mate. With all respect to zwobott, he ain't listening.

 

[zwobott]

your comments are valuable, and I do appreciate someone trying to help me out 🙂
what I am also trying to do is to google out as much as possible, and according to the manual: 'For the heating system to operate properly, the indicator
on the manometer (1) must be in the dark grey area
when the system is cold. This corresponds to a filling
pressure between 1.0 and 2.0 bar. If the pointer is in the
light grey area, please refill water.' And apart from it, everything seemed to be working perfectly fine until I started playing with CH temperature... 🙁

 

[zwobott]

I only cannot understand why everything worked great before my involvement ? I have come to terms that when you up CH temperature, water (its particles) accordingly will expand in size, so will the pressure in the system become bigger, I am not a plumber, just want to use my brain to find out how it works and find the right solution; don't blame me for that 🙂

 

[CES]

No-ones blaming you for anything, you asked the question and we have given you the answer to the question. Now we have deduced that by increasing the temperature you have experienced an increase in system pressure. This tells us that the charge within your expansion vessel is not what it should be. Before you increased the temperature you would not have noticed how much expansion was taking place and the expansion vessel was taking up a proportion of that, but now the expansion has increased the rise in pressure has become more noticeable. The solution is to either recharge or change the expansion vessel before any other problems occur due to the increase of system pressure.
Please don't think we are blaming, we only advise on here to the best of our professional ability according to the information given. I'd like to think I have given reasons for your problem, unfortunately I cannot change what the answer is to your problem no matter how it is explained.

 

[zwobott]

well CES, your latest post explained in plain English how it works; I am going to speak to/call a competent person and try to sort the problem out; at the moment, I just set CH on 55C as well as HW, so in the morning we won't have cold feet... 😉
Also,I've just checked pressure and it is 2,4 bar - 30 minutes after the boiler has finished its last cycle for today and is completely off; anyway, thank you for time spent on the issue

 

[CES]

Glad to be of service.

 

[jtsplumbing]

Why mess with somthing you do-not understand ! pressurized systems if messed with could be dangerous !! get some one out to check it .

 

[zwobott]

hi all, especially CES 😉 after all, I bled the system last Friday- when cold it was 2,2 bar; after the operation it stopped on 1,5 bar, so now when CH is on, pressure in the system is no higher than 2,2 bar and at the moment everything seems to be working fine. Thanks