Navien Combi Boilers

[hard-work]

The biggest makers of combis in the world from South Korea, with a decent reputation. The fluing is superb, using 2" plastic drain pipe for the flue. This fluing is cheap as well, especially in extended flue situations. Some of their models bang out the DHW flowrates. Some modulate down to 3 kW.

They have been in the UK small time for 3 years. The UK is the 2nd biggest market in the world for combis, which is an over-saturated market for makers.

Here is a fantastic video of it. Truly amazing:

More technical. He speaks in old money, BTUs, etc:

Anyone had experience of them?

 

[Elkato531]

Who knows, may be a fantastic product but its probably no better than most of the current manufacturers output. Most customers either want to go with a specific manufacturer or will take the advice of their installer. Most installers are going to recommend a boiler they are familiar with and which has good manufacturer support when things do go wrong. If you look at online marketing output, all boilers are apparently amazing.

 

[hard-work]

They are on sale in the UK and have been for about 3 to 4 years. They are also the biggest makers in the world. They looked very well specced, and well made, with high flowrate models and well priced. They even have a touch screen display. Combi boilers as we know them are pretty new in the USA with Navien having decent market share, which is also a large market. The flue lengths run up to 110m using 3 inch plastic drain pipe. When using extended flues they are the business, or even a normal short flue, as 2" drain pipe is used, so no rip-off cost for the flue when buying a boiler. They also do a system boiler as well.

Some people in the UK are buying and installing them. How they perform and service is what is missing.

 

[hard-work]

The vid states using the negative pressure gas valve 24 foot of 1/2" (15mm) pipe can be used supplying a 200,000 BTU (57kW) combi. The post meter gas pressures in the USA are about the same as here. They say ~8" wc (wg - water gauge here). A 57kW combi in the UK would need a 28mm gas pipe for most of its run. Using 15mm is quite a saving in many respects. The 40kW combi gives ~16 litre per min of DHW.

Negative pressure gas valves are used on pre-mix burners. I don't know if Navien use negative pressure gas valves on the combis in the UK.

 

[Dan Robinson]

The vid states using the negative pressure gas valve 24 foot of 1/2" (15mm) pipe can be used supplying a 200,000 BTU (57kW) combi. The post meter gas pressures in the USA are about the same as here. They say ~8" wc (wg - water gauge here). A 57kW combi in the UK would need a 28mm gas pipe for most of its run. Using 15mm is quite a saving in many respects. The 40kW combi gives ~16 litre per min of DHW.

Negative pressure gas valves are used on pre-mix burners. I don't know if they use negative pressure gas valves on the combis in the UK.

I think we have a record for the length of time it took for you to post something silly.

 

[hard-work]

Dannyboy cannot understand the vid and we know his knowledge of gas control is not that good. Dannyboy you are fun. It looks like Navien will kill Intergas at birth in the UK market.

 

[bernardgreen]

At least Navien claim a realistic 93% efficiency unlike some other manufacturers who claim to be more than 100% efficient.

That said American heating systems are significantly different to the UK "normal" and may therefor have a return temperature low enough at < 55°C (or < 131°F ) to make the boiler more efficient by being in condensing mode all the time it is firing.

 

[ianmcd]

they used to sell them in Plumbase here but they stopped, I thought they had pulled out of the UK market

 

[hard-work]

Navien are still available at Plumbase. They are wanting independent servicemen to be agents. I assume they have a full supply of parts - being Korean they would. Navien dominate the world market in combis: USA, Russia, Asia, etc. They are obviously serious at getting into the UK market. This is neat.

 

[hard-work]

Bernard, Baseboard (skirting) heating is common in the USA. They use copper finned tube.

 

[Dan Robinson]

Cheers maintap


I'll think my customer's pet dog has a better idea of the UK boiler market than you.

 

[hard-work]

Cheers maintap

A pleasure Dannyboy.

If Navien turn the screws on the 2nd biggest combi market in the world, they will take over as they have done in Russia and USA. Small operators like Intergas will die, Vaillant and WB will lose market share. They even have touch screen control systems and ready suited to Smart Phone control. All in the box.

Navien are quality, not imported Turkish scrap.

 

[Dan Robinson]

Navian are quality, not imported Turkish scrap.

And you've seen how many?

 

[hard-work]

Danyboy, keep up. Most have never seen an Intergas. When you mention the name to plumbers they say, "Uh!". I believe they have sold about 200,000 in the UK as well.

My initial post was requesting feedback by those who have had exposure to Navien. Not prattling about dogs.

 

[muggles]

A pleasure Dannyboy.

If Navien turn the screws on the 2nd biggest combi market in the world, they will take over as they have done in Russia and USA. Small operators like Intergas will die, Vaillant and WB will lose market share. They even have touch screen control systems and ready suited to Smart Phone control. All in the box.

Navian are quality, not imported Turkish scrap.

Navien arrived over here a couple of years ago, all fanfare and promises to do great things with their fairly unremarkable boiler (the potted PCB is a nice touch, and big flue lengths could very occasionally be useful, but that's all it's really got going for it). If they were going to make any significant dent in the UK market, they would have done by now, but instead both installers and reps are drifting away. I reckon another 2 years and they'll be gone