Any "Valliant" combi boiler experts out there

roddydogs

Right, just had a new Valliant Eco tec fitted the replace my old WB(non condensing) boiler. Its a higher output (31 compared with 24) But when trying to heat the room it keeps going to "Anti cycle mode" & the boiler switches off, despite being nowhere near the target temp. It is taking ages longer to increase the temp than the old boiler, really annoying I dont want to save a few quid on gas, I just want the room heated as quick as possible.
Is this a feature of all condensing boilers? Different water temps have been tried (currently 70c) but its still the same.Any ideas? Ta.

bambibashercol

Get the installer back.
The heating needs to be set properly at the boiler.. He needs to set the heating load in the boiler settings. If all your radiators total for example 11kw and the boiler is trying to through 28 kw into the radiators it won't run properly and will cycle on and off.

daveyjp

"But when trying to heat the room it keeps going to "Anti cycle mode" & the boiler switches off, despite being nowhere near the target temp."

I assume you mean target temp of the room stat, not the heating circuit?

With a rating of 31kw the water in the circuit will very quickly reach the 70 degrees it is set at. Once this is reached the boiler will cycle as the circuit water has reached the programmed temperature. It cycles to maintain the circuit temperature as heat is lost via the radiators.

If you want more heat from the system up the CH water temperature to max, which IIRC is 75 degrees on these boilers.

If the circuit water isn't reaching 70 degrees (the CH readout will tell you) you have a problem.

bambibashercol

As i said get the installer back.
It needs to be set correctly. The boiler is protecting it self as it's over sized for the heating circuit and the BOILER is over heating.
You can only push so much heat through the boiler.
Call the installer, he fitted it. He needs to fix it. Its a 2 minute job. Its even in the instruction book.

sk240

Just get the installer back, its probably a combination of being oversized, not balanced correctly, and the heating output is set too high.

If you want to look yourself, look at the manual to find the installer menu (press + & - at the same time, code is 17 from memory) and then change the D0 setting to 10kw maybe to start with. I believe the lowest setting is 6kw

This will allow the boiler to do a slow low burn and will reduce or even stop the anti cycling