Navien oil boiler - smart controls

[Roberto2019]

Hello All

I have more or less convinced myself to get a Navien oil boiler to replace my ageing (and leaking) Danesmoor. They seem to have good reviews, seem a bit more modern that others, and are quite a bit cheaper.

Question - is anyone here familiar with the various control options?

If you go for the Wireless Smart Thermostat (with programmer), I assume you also then need the Wireless Communication Module, to 'speak' to it, which plugs into the boiler. However, do you also then need the Wireless Wiring Centre? Or can you get away with a normal wiring centre, running the wires back down to the boiler from the airing cupboard (or wherever)....?

Many thanks

 

[muggles]

Is this for a combi or system/heat only boiler?

 

[Roberto2019]

Heat only/regular - standard open vented system, with a hot water tank

 

[muggles]

Hmm you might be rather disappointed if you're intending to keep it open-vented. It is technically possible to trick the boiler into running on an OV system but Navien don't like you doing it

 

[Roberto2019]

Thanks for the reply. Navien sell a heat only / regular boiler in addition to the system model.... surely the regular version is meant to work on an open vented system?

 

[muggles]

Yeah that's what I thought when I mistakenly fitted a Regular one on an open vented system without checking first. Cue a stressful 15 minutes trying to work out how to get rid of the flashing red low pressure error screen and make it play ball

 

[Roberto2019]

Is that because the boiler was still in 'system mode' and needed adapting (I assume from the factory the regular and system models are virtually identical) - how did you manage to fix it? I guess it is is all the set up of the DIP switches?

 

[muggles]

It's because the boiler is designed to be fitted on a sealed system, not an open one. Got it going by connecting the pump (which was fitted on the return by the boiler) to a flex & plug and plugging it in, turning it up to maximum, then slowly closing the flow valve until the boiler was satisfied there was sufficient pressure. I was then able to access the installer settings and reduce the sensitivity of the pressure sensor to 0.2 bar