System Boilers

[doitmyself]

Is it possible to use a System (i.e sealed system) as an Open Vent Boiler?

The pressure gauge would obviously read zero, but it there anything which will prevent it working?

 

[ecowarm]

Its possible, but you wouldn't buy a system boiler to use as an open vent boiler.

 

[doitmyself]

Its possible

Thanks - that's all I wanted to know.

but you wouldn't buy a system boiler to use as an open vent boiler.

I think you mean "I wouldn't buy ...."

 

[RoryD]

what will you do to the low pressure switch?

 

[armourer]

what will you do to the low pressure switch?

Thats just what I was thinking.
Most boilers with a pressure gauge have a low pressure switch, OK you could short it out but surely that's overriding a safety device?

 

[stevetheplumber]

old vailant were usable on open vent you just put the feed in where the safety valve vent but boilers have moved on no id be wary about doing it on a condenser

 

[Billy Bob Bob]

Thats just what I was thinking.
Most boilers with a pressure gauge have a low pressure switch, OK you could short it out but surely that's overriding a safety device?

yep,it could go pop if the system run out of water

 

[arran197]

I wouldn't, but I don't think they would class the low pressure switch as a safety device really, just prevents the boiler from firing with low water content as an indication to the user there is low water content. You don't get this problem with an open vented because the water supply is constantly there. The PRV is the safety device on a sealed system, like the open vent on an open vented system. That would be dangerous if taken away. The over heat stat and thermisters will still work the same.

There are boilers out there that will work on a vented system, such as a Baxi Solo HE. They are a straight swap for something like an old Baxi Solo.

 

[boblydon]

Sorry if i have missed the point here, but why not just alter the system and do away with the open vent, make it sealed???

If you need an open vented boiler then buy a heat only and use the existing pump etc

Bob.

 

[doitmyself]

Sorry if i have missed the point here, but why not just alter the system and do away with the open vent, make it sealed???

My existing system is 23+ years old and all the pipes are hidden, either under wood/concrete floors or behind plasterboard. I am therefore very wary of installing a pressurized system in case the system springs a leak, which would be very difficult and expensive to locate and repair. Testing beforehand is out of the question as that could also cause a leak. So I am left with using an OV boiler when I replace the 23 year old boiler.

So why buy a System boiler and make it OV? Simples! Because the pump of a SB is within the boiler and I want to do away with the external pump in the upstairs airing cupboard.

Just had a horrible thought! If the pump is in the boiler, where would the feed and vent pipes be connected?

Back to the drawing board! :mad2:

 

[mfgs]

Why do you want to do away with the external pump?

 

[doitmyself]

Why do you want to do away with the external pump?

It wasn't really doing away with the pump, but moving it to the boiler, so I could use the cable from the pump (upstairs in middle of house) to boiler (downstairs on side wall) for something else.

I have now found a way of overcoming this problem, so the need for a system boiler has gone away.

 

[RoryD]

Thats just what I was thinking.
Most boilers with a pressure gauge have a low pressure switch, OK you could short it out but surely that's overriding a safety device?

Actually I don't think it's a safety device mate. Some of the older worcesters actually have a kit to fit to neutralise this function. It may affect warranties etc.. Why would one want to do this anyway?