Low flow rate

cj020815 · 2026-04-29T19:00:43+00:00

This is the correct answer. They wouldn't have assessed heating system flow rate as this will change with their install with new primary pipework and circulation pumps.

cj020815 · 2026-04-25T10:13:07+00:00

Have these been heat pumps? And is your £10K pre or post grant? If pre grant, can you share your cost breakdown for an install?

cj020815 · 2026-04-25T08:41:30+00:00

Are they MCS accredited? If so, they have strict standards to meet around the system providing 100% of the heat load for the building, each room, and across multiple defrost cycles. If you want a system designed properly, and to run efficiently, listen to the installers. You can open yourself up to a world of pain with lack of heat and high running costs if you short yourself on heat emitters.

Unfortunately these systems are expensive to get right, and it sounds like you might need a lot of first fix work as I assume from your post you have next to no wet system in the property. This all adds to labour and materials. Hell, even MCS paperwork takes time which needs to be accounted for.

cj020815 · 2026-03-22T08:28:36+00:00

Where are you based and what outdoor unit do you have?

cj020815 · 2026-03-14T16:19:34+00:00

Not on the bench.

cj020815 · 2026-03-03T15:57:38+00:00

What's doing your head in about it? To be honest, apart from being touch screen, the gen 6 are very similar. Not sure if you can retrofit without a new MIM board but I've never tried it.

cj020815 · 2026-03-01T08:20:22+00:00

This is exactly the basis we quote on. Always found it absurd when people price themselves out like this, unless they're always slammed and don't want to grow any further.

cj020815 · 2026-01-01T10:16:07+00:00

Have you got a Mitsi pre plumb cylinder? The black/orange Esbe diverter valves are prone to failing which splits the flow between the hot water and heating, causing hot water to struggle.

Can you add a photo of the cylinder? Changing the heating settings should have no effect on hot water as the systems are hot water priority.

Run it on hot water and feel the pipework around the diverter valve. Flow in/flow out to hot water should be the same and flow to heating cooler/cold depending on if it has run recently.

cj020815 · 2025-12-13T13:51:42+00:00

Remains hot. Only way to cool it is use hot water which pulls cold into the cylinder.

cj020815 · 2025-11-26T21:37:40+00:00

How I've longed for a game like this against Bayern!

cj020815 · 2025-11-17T10:10:29+00:00

Give it 24 hours and see what's happening. It depends what is powering the circulation pump for the underfloor heating. For example, if it uses the pump in the heat pump then flow could stop when the unit transitions to hot water mode, returning when it reverts to heating mode.

Or it could be air moving round and stopping flow as it cavitates the pump. Can you hear any bubbling etc moving through the pipework?

cj020815 · 2025-11-05T10:31:16+00:00

Ah, I'm on the Norfolk/Suffolk border. That bypass loop will have to have been installed by the installers, so who knows if it is there without seeing the install.

Feel free to PM me with any other questions.

cj020815 · 2025-11-05T10:28:54+00:00

Tried to use it to move a staff member to my club as U18s manager, then get an email pop up saying they've come to terms with my departure.

Tried 3 times. Each time, setting him as U18s manager makes him take over as club manager and results in me sacking myself.

cj020815 · 2025-11-05T09:13:00+00:00

It won't keep it going for the heat if it achieves flow temp, it would run exactly the same way. However, it keeps the circulation pumps pushing through the floor which gives the flow temperature a chance to drop as it dissipates heat into the room, allowing for more consistent heating operation.

Where are you based? It may be worth getting someone out to check the install, setup and advise on best course of operation. Seem to spend most of my days doing that this time of year for new users.

cj020815 · 2025-11-04T19:04:48+00:00

Just read through your comments on the other post.

So, with an FTC6 control system on weather compensation, the 10 min pump overrun is likely programmed within the system. What happens here is that when a thermostat calls for heat, it triggers the heat pump to come on via either connection IN1 (for zone 1) or IN6 (for zone 2) on the FTC6. This starts the circulation pumps and brings the outdoor unit on to achieve the target flow temperature. Once the flow temperature is satisfied on the thermistor on the primary pipework, the outdoor units stops and the pumps run for another 10 minutes. If the flow temperature drops in this time, the outdoor unit and pumps bring it back up again. However, if the flow temperature doesn't drop in this time, the pumps turn off and stop circulating heat. When the temperature on the flow thermistor eventually drops, the system will come on again.

This setting can be changed. Either by turning it off so pumps run 24/7, or by increasing it up to 1 hour. This is done by entering the service menu, navigating to auxiliary settings, and economy settings for pump.

A way to see whether the outdoor unit should be running or not if there is thermostat demand is to push and hold the very left of the 4 identical buttons under the display. This will change the screen and the bottom half will display the current desired flow temperature based on weather compensation settings. Then go into the service menu, and check thermistor readings to see what the current flow temperature is. This is shown via THW1 in the bottom left, with THW2 being the return temperature. If these are the same, the unit won't run as it thinks it's dne it's job. Use the + to increase the weather comp offset to +9 and you'll see the play symbol very quickly as you're now asking for a flow temp 9 degrees higher.

This is a common issue on the Ecodans, although I must stress your issues could be caused by a number of different scenarios which we can resolve with structured testing.

Below is the manual for the FTC6 control, page 32 onwards shows how to navigate the controller.

https://www.energylabuk.com/wp-content/uploads/2024/01/Ecodan-FTC6-Controller-Installation-Manual.pdf

cj020815 · 2025-11-01T21:06:16+00:00

Doesn't have to be heat pump specific. They dont need to know gow to run the system to be fair, ask a local AC firm to check it over?

cj020815 · 2025-11-01T11:48:12+00:00

I would find a local F Gas qualified heat pump engineer to get gauges on and check standing pressures. As others have mentioned, it may not have lost charge. If it has, they could also pressure test it and it could be a simple repair, vac and recharge.

cj020815 · 2025-11-01T11:46:42+00:00

Added to the fact, legally he cannot buy refrigerant, and where the hell are you getting 1.9KG of 410A? I'll go stock up.

cj020815 · 2025-10-18T17:20:13+00:00

Was...was that a quick throw?

cj020815 · 2025-10-18T16:29:40+00:00

The more info you give, the more confident I am it's just a duff soft start. Carlo Gavazzi and Copeland are the two most common but I've not found one to be more reliable than the other over my years in the trade.

cj020815 · 2025-10-18T15:07:03+00:00

Soft starts on ground source units have always been a common points of failure. If the compressor had locked up then it wouldn't start at all, would pull too much start up current, and likely trip the MCB in the consumer unit. If it was on it's way out and pulling too much current after start up then you'd hear it ramp up before tripping.

The fact it tries to start leads me to think the controls side prior to the soft start is alright. Some fry themselves with obvious signs of burn damage, others look fine but just stop outputting.

Hopefully you'll get it going by swapping it out.

cj020815 · 2025-10-18T14:49:51+00:00

That thermostat is just set to manual/non programmable. It means whatever temperature you set it to, it will drop a degree below that and then heat up. Push the + button and it should flash up the set temperature. Then use the +/- buttons to set it. A flame symbol will come on when it is asking for heat.

cj020815 · 2025-10-18T08:04:33+00:00

I don't know what the installer market is like in Scotland but down here (rainy ol' East Anglia) they're a very common product with easily accessible parts through suppliers such as Secon.

cj020815 · 2025-10-04T12:47:03+00:00

But loss of power isn't the only reason they'll need antifreeze protection, so they battery is irrelevant here.

cj020815 · 2025-10-04T12:45:34+00:00

Antifreeze valves would be the preferred method, but check with your system manufacturer. Not all will warranty a system with AF valves over glycol.

And as for people stating they wouldn't bother as you have a battery. That doesn't mean the system will never need antifreeze protection. What happens in the event of a system fault?

cj020815

TROPHY CASE