when the heating comes on it starts warm air convection currents which may well increase exposure?

We aim for around 50% humidity and our house would be in a worse state if I didn’t do this. 

Unless you have an extremely unusual reason for a damp house, a dehumifier may be an issue.  Unusual reasons include a new house drying out, driving rain getting through brickwork, rising damp.  

The reason I say the above is that in my experience it's harder to control the level of CO2 to an acceptable level(<1000ppm) than reduce the humidity in a house in the UK down to 50% RH (generally considered the optimum, see piccy).  The use of a dehumidifier may then remove moisture from the air, while leaving the high level of CO2.  High CO2 levels (>1000ppm) internally causes drowseyness, loss of concentration, headaches.  In contrast, opening a window, or using heat recovery ventilation, controls both humidity and CO2. 

I recommend that you get a CO2 monitor - they used to be expensive, but can be bought these days for £40 or so.

Humidity is normally between 50-60% we have a dehumidifier in our living room which is on a timer a few hours at night, and when I see it’s getting too high. 

Firstly I love my heat pump. This will be my first winter with mine and so far so good. Really happy with its performance.

Except for one thing (and it's something I had problems with with my gas central heating too.)

Does anyone else get sinus problems and headaches from the toasty heat? I'm keeping my home warm with weather compensation aiming for 20 degrees (mostly because if I go lower my partner complains of being cold) but I'm really struggling with breathing and head pain issues. Possibly a bit worse now because the heating is staying on all the time at a lower temperature overnight (which is not something I previously did).

Any advice for how to make myself more comfortable? Sorry if this is a silly question but I couldn't see anything about this and as as person with two chronic illnesses (unrelated that aren't causing these symptoms) this means I am in pain a lot and this sort of thing has an impact on me. Working from home too.

I appreciate this is probably due to drier air and dust but I also live in a victorian semi (so damp can be an issue) and I need something a bit gentler on my house than a humidifier.

Lots of advice online for gas system and other systems, but I'd appreciate some thought and feedback from other heat pump owners. 

Hi,

It might be worthwhile buying a humidity meter, so that you can see if it is too high or too low. You can then experiment with methods of getting it to your liking.

If it’s less than say 40% you might. Want to pop a dish of water on the radiators to evaporate and raise the humidity so it’s not as dry. 

Except for one thing (and it's something I had problems with with my gas central heating too.)

Does anyone else get sinus problems and headaches from the toasty heat? I'm keeping my home warm with weather compensation aiming for 20 degrees (mostly because if I go lower my partner complains of being cold) but I'm really struggling with breathing and head pain issues. Possibly a bit worse now because the heating is staying on all the time at a lower temperature overnight (which is not something I previously did).

Any advice for how to make myself more comfortable? Sorry if this is a silly question but I couldn't see anything about this and as as person with two chronic illnesses (unrelated that aren't causing these symptoms) this means I am in pain a lot and this sort of thing has an impact on me. Working from home too.

I appreciate this is probably due to drier air and dust but I also live in a victorian semi (so damp can be an issue) and I need something a bit gentler on my house than a humidifier.

Lots of advice online for gas system and other systems, but I'd appreciate some thought and feedback from other heat pump owners.