Vaillant EcoTec Plus 428

[jaydebruyne]

It's not going above 42 degrees. Burners on. Have checked thermostat and it's working fine. It ramps up every now and temp goes to 65 degrees for about 10 seconds and then ramps straight back down and temp goes back to 42...????

Didn't go as far as to check the thermistor as it was bloody late and I only went to change the pump. So will go back next week.

But I thought thermistors either worked or not at all? Can they go rogue? Give dodgy readings rather then either working or not at all?

 

[townfanjon]

Its doing that after you changed the pump

 

[jaydebruyne]

Its doing that after you changed the pump

No it did it before hand as well but but after a while of me being there the temp sorted itself out, but the pump was weak so wasn't pushing it to downstairs rads - it's a big house.. about 15 rads over 3 floors - done in 22mm from the boiler which is top level. Undersized pipework is killing the pumps every 2 years so I put in an alpha2L and left it on the variable flow. But this time the temp didn't sort itself out

 

[gassafe]

Sounds like sludge to me... it ramps up to 65, gets too hot & clicks off maybe? Does it click off the burners or just ramp down?

If it clicks off it won't refinement the burners for another 3 minutes or so anti-cycle time so it'll be pretty inefficient

 

[jaydebruyne]

Sounds like sludge to me... it ramps up to 65, gets too hot & clicks off maybe? Does it click off the burners or just ramp down?

If it clicks off it won't refinement the burners for another 3 minutes or so anti-cycle time so it'll be pretty inefficient

Just ramps down, burner stays on. There's sludge in some downstairs rads so I already recommended a flush and a few new valves needed.

It wouldn't have anything to do with the fact the entire system is piped in 22mm? For a house the size it is (3 floors and about 15 rads) I'd have thought at least 28-35 and then dropping into 22 nearer the rads..

 

[Leo21]

They monitor the heat on flow and return, set the kw and temp to max. Maybe a bypassmigyt help. Or speak to Vaillant I'm sure there are settings they can put into help you.

 

[jaydebruyne]

How do you set the kW output on these boilers? Jumper or switch on the board?

 

[Last Plumber]

How do you set the kW output on these boilers? Jumper or switch on the board?

Do it in set up panel.
How old is it ?

 

[jaydebruyne]

Do it in set up panel.
How old is it ?

Not sure, it don't look that old

 

[Last Plumber]

How do you set the kW output on these boilers? Jumper or switch on the board?[/QUOTE

I did post how to but I realised it's on wrong forum.

 

[Last Plumber]

Not sure, it don't look that old

Has it got knobs or buttons

 

[jaydebruyne]

Has it got knobs or buttons

Knobs for temp control so the older model

 

[Leo21]

I have to read the book on that one.

 

[Last Plumber]

Knobs for temp control so the older model

Press i and + at same time that gives you a reading on display of d0

Press i and that tells you what the thing i set to in Kw.

Alter with + and - and to set the target value press and hold i for about 5 secs until the display returns to d0

I cant see this being the solution. I would check thermistor and check for blockages in the two flex pipes inside, if it's the one with those ( look like rad hoses)

 

[jaydebruyne]

Press i and + at same time that gives you a reading on display of d0

Press i and that tells you what the thing i set to in Kw.

Alter with + and - and to set the target value press and hold i for about 5 secs until the display returns to d0

I cant see this being the solution. I would check thermistor and check for blockages in the two flex pipes inside, if it's the one with those ( look like rad hoses)

Oh the flow / return pipes with the black rubber connection pieces with clips - I've gotta replace a return pipe on Wednesday cos that rubber connection is leaking at both ends!

I've ordered a thermistor just in case.. going there this week.

Cheers for the info mate, much appreciated

 

[Last Plumber]

Oh the flow / return pipes with the black rubber connection pieces with clips - I've gotta replace a return pipe on Wednesday cos that rubber connection is leaking at both ends!

I've ordered a thermistor just in case.. going there this week.

Cheers for the info mate, much appreciated

No worries, Those rubbers have mesh strengtheners inside that corrode for fun. I think you get both as a pair in a pack. Be careful not to let the bits fall into anything else.

I find its better to take the full pipe out and replace them away from the boiler, easier too.

Also, there is a filter in the section behind the flow switch, to check it, whilst its drained,remove the flow switch and you can see if its clean or not. It can be a pig to get out so if you look from there it will save you struggling with it. Theyre plastic and break easy too so if you do need to clean it be careful taking it out.

Silicone grease will be handy putting things back together

 

[jaydebruyne]

No worries, Those rubbers have mesh strengtheners inside that corrode for fun. I think you get both as a pair in a pack. Be careful not to let the bits fall into anything else.

I find its better to take the full pipe out and replace them away from the boiler, easier too.

Also, there is a filter in the section behind the flow switch, to check it, whilst its drained,remove the flow switch and you can see if its clean or not. It can be a pig to get out so if you look from there it will save you struggling with it. Theyre plastic and break easy too so if you do need to clean it be careful taking it out.

Silicone grease will be handy putting things back together

Those pipes with the rubbers are discontinued now and only supplied as full copper tubes.. which is good. I'll see about the filter behind the flow switch..

Cheers mate

 

[Tonycane]

Those black rubber tubes block for fun causing poor flow

 

[ShaunCorbs]

Just a heads up and sorry jay for going off optic but you have just made me remember something

The new iq from vaillant have re introduced them stupid black hoses again

 

[jaydebruyne]

Thing is though, if it were poor flow wouldn't the boiler be overheating? Rather than staying at 42 dc?

 

[Last Plumber]

Thing is though, if it were poor flow wouldn't the boiler be overheating? Rather than staying at 42 dc?

Not necessarily no

 

[jaydebruyne]

Just a heads up and sorry jay for going off optic but you have just made me remember something

The new iq from vaillant have re introduced them stupid black hoses again

Whyyyyyyyyy!!?!?!?!?

 

[jaydebruyne]

Not necessarily no

Why not?

 

[ShaunCorbs]

Whyyyyyyyyy!!?!?!?!?

Cheaper and able to sell kits when they break

 

[Leo21]

Why not?

It would just modulate down.

 

[jaydebruyne]

It would just modulate down.

Is that a Vaillant thing then cos worcesters just overheat!!

 

[Leo21]

Is that a Vaillant thing then cos worcesters just overheat!!

Yeah, they read flow and return temps.
There's also a stupid filter on these, it's placed so it stops dirt leaving the boiler! I've had an 824 that was doing a similar thing, I removed the filter. I had to break it into pieces to remove it, and then flushed the heat exchanger through. Into a bucket, arkward but do able. The filter is on the bottom left, where the flow leaves the boiler.

 

[jaydebruyne]

Yeah, they read flow and return temps.
There's also a stupid filter on these, it's placed so it stops dirt leaving the boiler! I've had an 824 that was doing a similar thing, I removed the filter. I had to break it into pieces to remove it, and then flushed the heat exchanger through. Into a bucket, arkward but do able. The filter is on the bottom left, where the flow leaves the boiler.

So basically get a new filter as I'll break the existing one trying to get it out! Stupid place to put a filter.. I saw an install where someone had put a magnaclean on the flow lol

 

[Leo21]

No, just break it out and leave it out. It actually doesn't benefit from being there imo.