Newby heat pump questions

km1500

my gas boiler is on its last legs and I am thinking of having a cozy six heat pump installed by octopus. 

1. obviously I will have a hot water tank installed as part of the installation but once up and running is it possible to have the heat pump supply radiators only i.e not heat the dhw - maybe a setting somewhere?

2. I would currently plan to turn the heat pump on when it gets cold (say November) and then turn it completely off when it starts getting warmer eg march. would this cause any problems?

3. there was no landline or router at the property so we would lack of internet cause any problems. a workaround would be to use the hotspot on a mobile phone but obviously that would not be continuous internet 

4. I'm used to a gas boiler so not quite sure about the running of the heat pump when it's heats the radiators. do I just set a flow temperature for the water and leave it at that i.e no thermostat or anything inside?

sammyjammy

What kind of house is it?  Well insulated?

km1500

yes 3 bed, well insulated

Reed_Richards

1.  Yes, you can turn off heating the hot water.  On my heat pump it's a single button press and I did it accidentally once.  I can't see why anyone would want to do this, though.  An alternative might be to keep your hot water as lukewarm as you like.
2. I don't think that should be much of a problem but I think your heat pump would prefer being run for a short while once a week.
3. My heat pump does not use any internet connectivity.  I doubt that a lack of internet would be a problem but I don't have specific knowledge of the ones Octopus install.
4. Running a heat pump at a fixed flow temperature is entirely feasible but not the most economical way to run one.  I imagine Octopus will give you an indoor thermostat.  If your system is very well tuned it is possible to operate a heat pump in a manner where the flow temperature is determined by the outside temperature, "Weather Compensation", and the indoor thermostat just functions as a backstop.    

km1500

thanks very much that clears a few things up

Netexporter

Do you have a smart meter so that you can access a suitable tariff to keeps costs down?

km1500

yes I do thanks

my use of a heat pump is likely to be - turn it on when the weather starts to get very cold and turn it off in the spring. Space heating only, no dhw.

70sbudgie

Can I ask why you don't want the new heat pump to heat dhw? Is that being heated by other means? 

The reason I ask is because I have been looking into separating dhw and heating and wondered if you have a solution for that.

Reed_Richards said:

...

2. I don't think that should be much of a problem but I think your heat pump would prefer being run for a short while once a week.

...

Why is this? Does it mean that HPs don't like being turned off for extended periods i.e if providing just heating and therefore turned off over the summer..

NedS

70sbudgie said:

Can I ask why you don't want the new heat pump to heat dhw? Is that being heated by other means? 

The reason I ask is because I have been looking into separating dhw and heating and wondered if you have a solution for that.

Reed_Richards said:

...

2. I don't think that should be much of a problem but I think your heat pump would prefer being run for a short while once a week.

...

Why is this? Does it mean that HPs don't like being turned off for extended periods i.e if providing just heating and therefore turned off over the summer..

It's not so much the heat pump itself, but things like the water circulation pump which may seize if not used for months on end. My heat pump will automatically run the circulation pump(s) for 5 mins every 24h if the system is left switched off to stop them seizing. Water pumps only draw ~50w or so, so not an issue for them to run for 5 mins every day during summer when the heating is off.

Why would you not want to use your heat pump to heat your hot water in summer? How will you heat the hot water if not by the heat pump?

Rodders53

Heat pumps compressors frequently have lubricating oil in the gas system that needs to be circulated to keep things in tip top condition.

Motor vehicle aircon compressors have seals that dry out and allow the gas to escape.  Hence the recommendation to run all year round.

SOME poorly designed heat pumps had a 'vampire load' to heat said crankcase oil and that may be a concern for some older installations.

How will / do you heat your hot water (cylinder)? 

km1500

dhw is provided by other means so essentially I want my hot water cylinder to remain cold

I could of course use the heat pump to heat dhw but it would be wasted and this is a money saving site!

during the summer the heat pump would be off and during the cold months it would be on heating the radiators only 

a good point about running the heat pump occasionally during the summer months just to keep things freed up so to speak thanks for that suggestion

my thoughts about not switching the heat pump off completely for eight months of the would be the vampire cutrent drawn just having it sitting there switched on but doing nothing