Drayton 2 Port Valves - switch driving me nuts

[Harry Bloomfield]

Thanks. Do you happen to know if it's possible to test the frost stat operation so I can see exactly what happens when it kicks in? Save having to trace all the wiring in both boiler and junction box. Because if our installation works the way you say then I need to look for another fault, something which brings on the boiler and pump with both valves closed.

Turn the frost stat up until it clicks on, you should be able to then see what has powered up.

 

[Terrywookfit]

The frost stat is set to 2 ° and is non adjustable,
Fit a temp link between 1 and 5 with programmer set to off.

My guess is you have no pipe stat fitted and the frost stat is firing burner and pump with no zone valve open.

 

[Alec_t]

pump running with both valves closed

Do you have an automatic bypass, so that there is always some flow even with both 2-port valves closed?

 

[ianmcd]

The frost stat is set to 2 ° and is non adjustable,

Depends on make , some are adjustable Terry

 

[aesmith]

Not much progress but I was able to observe my "fault" again last night. It came on around 2 hours after the programmer switched the heating off and I confirmed that boiler and pump were both running, both valves closed, and the temperature of flow and return pipes felt the same as if the heating was on normally. I ran like this for something over an hour, which seems a long time to get the internal temperature up above 2 degrees.

That's consistent with Terrywookfit's guess that there's no frost pipe stat. Or that it's fitted but faulty.

Bypass is a manual gate valve. I opened it a bit more and set the pump to its lowest speed so things weren't labouring so much.

I've asked the installers again about how it was configured. If I don't hear back I'll see if I can get at the boiler control panel to see what links are fitted. I've asked then to confirm that I won't void the warranty by doing this, if I don't hear back I'll take that as clearance to go ahead.

 

[aesmith]

Depends on make , some are adjustable Terry

It's Grant, a "Vortex Pro". The documentation suggest non-adjustable, and also doesn't say where it's located ..
"The boiler is ftted with a pre-set internal frost protection thermostat. If the air temperature around the boiler falls below 2°C, then this thermostat will be activated to protect the boiler from freezing."

 

[oilhead]

Is this an external boiler?

 

[aesmith]

Yes, external.
https://www.grantuk.com/products/oil-fired-boilers/vortex-pro-external/

 

[Terrywookfit]

It is configured as it left the factory.
How long has it been fitted ?
It certainly does not comply with building regs in England.
Any competent installer would have fitted a pipe stat and wired it to the motorised valve.
The installation instructions leave it open so the installer can fit S Y or UFH .
A gate valve is not a suitable bypass.

 

[aesmith]

It's just over two years so still within warranty. It's S system. I've asked these questions of the installer and I would be pretty disappointed if the installation was non compliant because we've used them for a few jobs and they've been OK. I suppose it's possible something slipped between the cracks so to speak because a third party electrician did some of the electrical works. Which particular English regulation would it be breaching?

They're the same guys who we got to convert to S system around 9 years ago, from the horrible hybrid pumped/gravity system that was there originally. The pump definitely predates that work, but I can't say whether the bypass was new then or pre-existing.

 

[Terrywookfit]

It's just over two years so still within warranty. It's S system. I've asked these questions of the installer and I would be pretty disappointed if the installation was non compliant because we've used them for a few jobs and they've been OK. I suppose it's possible something slipped between the cracks so to speak because a third party electrician did some of the electrical works. Which particular English regulation would it be breaching?

They're the same guys who we got to convert to S system around 9 years ago, from the horrible hybrid pumped/gravity system that was there originally. The pump definitely predates that work, but I can't say whether the bypass was new then or pre-existing.

https://www.google.co.uk/url?sa=t&r...Regulations/&usg=AOvVaw3QUDyYKuQLMJp7lWbRMKV-

 

[aesmith]

Thanks, found the relevant bit from the link. Even if that's not included in Scottish building regs it's still a convincing argument of good practice. Hope to check all the wiring connections over the weekend and take it from there. I think I can leave the CH valve on the manually open setting overnight, that doesn't open fully so doesn't operate the microswitch, but would allow some flow.

 

[Terrywookfit]

Without the pipe stat you will get constant heating if frost stat activates.

 

[aesmith]

I don't know where the 2 Degree frost stat is located, but I assume once the boiler's run for a while it will have warmed the module up enough for that stat to cut out. Not far from ideal of course, but it's what we have (probably) at the moment. I can't think why we didn't notice this over the last two winters, which also makes me wonder if the frost pipe stat is installed but failed.

 

[Terrywookfit]

If that is true then why was the zone valve not wired to open.
The frost stat will be mounted inside the boiler control panel....You can also check what is connected and links for pipe stat.