Hive Issue - Tried everything

[scottrotherman]

So my system is as follows.

Gravity fed system with 3 port valve and tank stat.

The circulation pump live is wired through the tank stat. We have a dual Chanel Hive stat. When it calls for heating is lights up for both heating and hot water (this is to run the pump?). Hive has had gravity mode selected.

Everything was working fine until the last month when the heating will only come on when the hot water needs to be heated. On heating only the pump doesn’t run if the hot water is at setpoint even though the hive is activating heat and water. Even when it’s running when I turn the tank stat down the pump stops and heating stops. The pump love is wired through the tank stat call (it has always been like this)

We have to power everything down and back up.

We have replaced the tank stat, 3 port valve and even the hive but the problem still is here.

No wiring has been changed from when we moved in.

Help please

 

[CBW]

What make/model of 3 port? Could be a faulty new one.

 

[Mottie]

I know absolutely zilch about heating/wiring so I’m probably talking out of my a-hole here but I always thought that the power to run the pump should come from either the boiler or the wiring control centre. How can it be controlled through the tank stat? Perhaps the whole thing needs re wiring correctly?

 

[scottrotherman]

What make/model of 3 port? Could be a faulty new one.

It’s a Drayton MA1. This was replaced in January. I mean it could have failed after 6 months. Would this not working properly cause the pump to not kick in?

 

[scottrotherman]

I know absolutely zilch about heating/wiring so I’m probably talking out of my a-hole here but I always thought that the power to run the pump should come from either the boiler or the wiring control centre. How can it be controlled through the tank stat? Perhaps the whole thing needs re wiring correctly?

It does come from the wiring control centre. The live to the pump comes from the call to the tank stat. When I select heating in the hive app both the heating and hot water comes on (person on hive helpline said this is correct) due to it being gravity fed.

It can’t be the wiring as everything worked a month ago fine.

 

[Johntheo5]

Just to be clear, do you have gravity HW and pumped CH or is it a fully pumped system with a feed and expansion tank in the attic?, open vented.

If fully pumped you should switch the hive to non gravity mode?

 

[scottrotherman]

It’s gravity HW and pump central heating. Got a tank in the loft feeding the hot water tank and a feed an expansion tank for the central heating

 

[Johntheo5]

I have exactly the same set up, ie a vented HW cylinder and a feed and expansion tank in the attic, this is sometimes termed a gravity system even though the HW&CH are normally, like mine, fully pumped.
The new hive comes defaulted in the non gravity mode (LED colour indication I think) and has to be re selected to gravity mode which I assume you have done.

"Even when it’s running when I turn the tank stat down the pump stops and heating stops."
If its operating in gravity mode and you turn off the CH then it should just turn off the pump but leave the boiler firing if the cylinder stat isn't satisfied?.

 

[Mottie]

Years ago when we had gravity hot water, and pumped heating, we had to buy a 3 port valve (as well as other bits, including a tank stat) to convert it to a fully pumped system. Only reason was that the boiler was floor mounted and the hot water tank was at the top of the airing cupboard and I wanted to move it to the bottom. I didn't think you needed a 3 port valve or a tank stat if you were using gravity to heat your water. Perhaps I had a different type of system?

 

[Johntheo5]

Here is a Gravity HW System with a 2 Port Valve, this 2 port seems to have a extra wire? but is a honeywell 28mm V4043H so I suppose a 3 port midposition can be wired to do the same?.

Apparently this is the 6 wire 2 port 28mm honeywell, other manufacturers also do them and (including Honeywell) do a 22mm one.
V4043H1106

 

[ianmcd]

Hive has had gravity mode selected.

But you do not have gravity HW , set it to fully pumped, Gravity fed as you call it and gravity HW are totally not the same thing, you have a mid position valve so you have a Y plan fully pumped system NOT A GRAVITY HW SYSTEM, they are completely different your Hive is set wrong

 

[Johntheo5]

Looks that way except only ports AB & B are connected to the HW with port A blanked off and somehow the valve is wired to accomodate this, very easy to check out, if the three ports are being used then its a fully pumped system?.

 

[scottrotherman]

But you do not have gravity HW , set it to fully pumped, Gravity fed as you call it and gravity HW are totally not the same thing, you have a mid position valve so you have a Y plan fully pumped system NOT A GRAVITY HW SYSTEM, they are completely different your Hive is set wrong

Ahhh right. I just set it to what I was told by the person on the Hive helpline. They asked if I had a tank in the loft that fed the hot water tank and when I said yes they said it needed to be put in gravity mode.

So I have a fully pumped open vented system (a loft tank for heating and a loft tank for hot water)

A question then, the hive was fitted over a year ago and worked fine with no problems. Why would it suddenly stop working properly if it was set wrong in the first place.

Thanks

 

[Johntheo5]

Because the hive was set to pumped? Is it OK now and are there 3 pipes attached to the 3 port valve?

 

[scottrotherman]

It appears to be working now and there are 3 pipes attached to the mid position valve. Hopefully this has fixed the issue.

Thank you for your help